Only $2.99/month

Genitourinary EXAM MASTER

Terms in this set (141)

orrect answer:
Non-tender, fluid-filled lesion that transilluminates

Explanation The correct answer is a non-tender, fluid-filled lesion that transilluminates. A hydrocele is a collection of fluid within the tunica vaginalis. It is non-tender, usually develops slowly over time, and will transilluminate when a light is held up to the scrotal wall. Patients can experience fluctuating size of the hydrocele, swelling of the scrotum or inguinal canal, heavy sensation within the scrotum, and do not typically experience any pain.

Solid mass within the testicle that does not transilluminate is not the correct answer. Solid masses that are actually in the testicle itself are malignancies until proven otherwise. Patients may have a reactive hydrocele in addition to the malignancy, but hydroceles do not actually present as solid masses. In addition, hydroceles will transilluminate, whereas testicular malignancies will not transilluminate on examination.

Painful swollen retracted testis that does not transilluminate is not the correct answer. This more closely describes testicular torsion as opposed to a hydrocele. Testicular torsion is painful, whereas hydroceles are not painful. Testicular torsion can also cause one testicle to retract and will not transilluminate upon examination. Testicular torsion is a urologic emergency, whereas hydroceles are often not even treated.

Non-tender mass with the consistency of a "bag of worms" without transillumination is not the correct answer, as this description is more closely associated with a varicocele. Both hydroceles and varicoceles are non-tender, but hydroceles will transilluminate and varicoceles will not. Since a varicocele is a venous varicosity without the spermatic vein, it is often described as having the consistency of a "bag of worms" on examination. It will also decrease in size if the scrotum is elevated or the patient lies supine.

Painless cystic mass containing sperm that transilluminates is not the correct answer, as this more closely describes a spermatocele. A spermatocele is usually a palpable cystic mass that is free-floating above the testicle and will transilluminate upon examination. Spermatoceles and hydroceles are similar in that they are painless, harmless, and usually do not require treatment.
Correct answer:
Acute tubular necrosis

Explanation
The clinical and laboratory findings of the vignette point to the diagnosis of acute tubular necrosis (ATN). In cases of ATN, cells heal completely by regeneration. Epithelial cells that line the kidney tubules are destroyed by ischemia (e.g. hypovolemic shock, sepsis, cardiac heart failure), toxins (e.g., aminoglycosides, amphotericin B as in this case, contrast media, lead, cisplatin), myoglobinuria in rhabdomyolysis, or hyperurecemia in acute tumor lysis. Re-absorptive mechanisms of sodium and water are lost with the tubular cells and acute renal failure occur. 2 features corroborate for the regeneration in ATN to be complete: 1) necrosis occurs in a patchy pattern; 2) the collagen framework of the tubules (epithelial basal membrane and the interstitium) remains intact. The existing epithelial cells replicate using the basement membrane as a guide, and they bring the kidney back to normal. After regeneration is complete, the damage is undetectable, even microscopically.

In contrast, healing will take place by repair when the causative process affects the kidney collagen framework. While enzymes released by inflammatory cells in chronic pyelonephritis damage this framework, an infarction leads to its total collapse. Because of the history of previous cerebral infarction and fungus endocarditis, the possibility of another embolization with kidney infarction in this case is high. However, the clinical and laboratory findings do not support this diagnosis.

Diffuse cortical necrosis (DCN) is an acute generalized cortical infarction of both kidneys, leading to atrophy of the cortex with preservation of the medulla. DCN is the pathological progression of ATN: once rapidly corrected, acute renal ischemia leads to ATN. A more prolonged ischemia may lead to DCN. DCN is associated with late pregnancy complications (e.g., placental abruption) and septic shock.

Polycystic kidney disease is a genetic condition that leads to the formation of multiple cysts and irreversible destruction of the kidney parenchyma.
Correct answer:
Gram-negative bacteremia

Explanation
The correct response is Gram-negative bacteremia.

Some degree of enlargement of the prostate is extremely common from the age of 50 onwards, but this type of enlargement often produces either minor symptoms, or no symptoms at all. However, benign hypertrophy of the gland results in elongation and tortuosity of the prostatic urethra, and the median lobe may become a large, rounded, swelling overlying the posterior aspect of the internal urinary meatus. Here, it can act like a ball valve, producing urinary obstruction. The deranged anatomy in the region of the internal meatus, may allow urine into the prostatic urethra. The urine in this situation sets up a desire to micturate, and this produces one of the most common symptoms of prostatism, namely, frequency. This is particularly worrisome to the patient at night, as it interferes with his sleep. The obstruction, and instrumentation to relieve it, predisposes to urinary infection. The obstruction to the outflow of the bladder may result in renal failure and uremia. Gram-negative enteropathogens are the most common cause of urinary tract infections and intra-abdominal sepsis, especially post-operatively, in the acute abdomen. Septicemia causes high fever, shivering, headache, and rapid breathing; it may progress to delirium, coma, and death.

Myocardial infection gives rise to chest pain, which is usually of greater severity and duration than in angina, and is associated with nausea, vomiting, sweating, and extreme distress. The patient may be cold and clammy with tachycardia, hypotension, cyanosis, and mild pyrexia (Postoperative bleeding may lead to hypotension and hypovolemic shock, unless fluid volume is rapidly replenished.

Arrhythmias may give rise to tachycardia and bradycardia, which are sometimes felt as palpitations. They may also present with their hemodynamic consequences: dyspnea, angina, collapse, or "funny turns". Corresponding EKG changes are diagnostic.

Pneumonia is relatively slow in onset, with symptoms of systemic upset, fever, pleuritic pain, cough, and green sputum (may be scanty at first, or, "rusty" in color, if due to pneumococcal). On examination, there will be signs of consolidation, or just localized crepitations. Tachypnea is a valuable sign, especially in the elderly, in whom there is high index of suspicion.
Correct answer:
Anticholinergic

Explanation
Urge incontinence is defined as involuntary loss of urine occurring for no apparent reason together with a feeling of urinary urgency (a sudden need or urge to urinate) that represents a hygienic or social problem to the individual. The most common cause of urge incontinence is involuntary and inappropriate detrusor muscle contractions. The drug you will suggest is anticholinergic (like Oxybutynin). It will relieve urinary and bladder difficulties, including frequent urination and urge incontinence by decreasing muscle spasms of the bladder, increasing the capacity of the bladder, and delaying the initial urge to void. It is a competitive antagonist of M1, M2, and M3 muscarinic acetylcholine receptors, and it can act as spasmolytic on bladder smooth muscle at higher doses. Anticholinergic side effects are dry mouth, difficulty in urination, constipation, blurred vision, tachycardia, drowsiness, and dizziness.

Cholinergic drugs will cause slowing of the heartbeat and an increase in normal secretions. For this reason, patients who already have a problem with incontinence should not be advised to use these drugs.

Epinephrine is not indicated in this patient. Epinephrine stimulates the ends of the sympathetic or inhibitory nerves of the bladder, with the effect of relaxation of the bladder muscles and the increase in tone and rate of contraction of the ureter. The secretion of urine is increased synchronously with the rise in arterial pressure. It will also cause overacting heart, palpitation, and vomiting.

There is no need for antibiotics in a patient with normal urine analysis for a problem that lasts several months.

Botulinum toxin is given as intradetrusor injection in patients who have failed pharmacological therapy. It has been shown to decrease episodes of urinary leakage by preventing the release of acetylcholine from presynaptic membrane. It is also indicated for urinary incontinence in patients with neurologic conditions (e.g., spinal cord injury, multiple sclerosis). It sometimes can cause urinary retention given as intradetrusor injections and occasionally headache, light-headedness, fever, abdominal pain, and diarrhea (not necessarily a direct result of Botox).
Correct answer:
Lithotripsy

Explanation
This patient has a 7mm ureteral stone and will likely require surgical intervention, such as lithotripsy, for this stone to pass.

Peitrow and Micali note that 90 to 98% of stones <5 mm are likely to pass on their own, although sometimes >30 days are needed for this to occur.

A variety of agents may assist in stone passage. Deflazacort, a steroid, decreases ureter edema and may facilitate stone passage through the ureter. Nifedipine and tamsulosin decrease ureter spasm, facilitating smoother stone passage through the ureter. Analgesics, particularly opioids and non-steroidals, decrease the pain associated with stones lodging in the ureter.

In the case of larger stones (>5 mm), passage is unlikely.

Surgical interventions for stone removal include lithotripsy, a procedure which uses sound waves to break stones into smaller pieces which can be passed.

Other procedures to assist in stone management include ureteral stenting, percutaneous nephrostomy tube placement, open surgical stone removal, and retrograde ureteral stone removal. However, since open surgical removal is an invasive procedure, lithotripsy is the first choice. Lithotripsy involves the usage of shock waves to crush stones in the renal calyx. It may be done as an outpatient procedure. Extracorporeal shock wave lithotripsy involves waves directed from outside; whereas intracorporeal shock wave lithotripsy consists of insertion of a percutaneous nephroscope and then crushing of the stones.
Correct answer:
Normalize weight

Explanation
This patient will benefit from lifestyle modification to normalize her body weight post-pregnancy. Dietary modifications, exercise, breastfeeding, and nutritional counseling may be helpful. She was overweight pre-pregnancy, with a BMI > 30 kg/m2. Obesity is a known risk factor for incontinence. It is also a risk factor for insulin resistance and diabetes, which may also contribute to various forms of incontinence. None of the other options listed below will help prevent incontinence; in fact, they may be risks for incontinence.

Incontinence is common in pregnancy. Fetal compression of the bladder plus large volumes of urine due to suggested volume intake and increased glomerular filtration rates may contribute to this. Postpartum, vaginal birth, and changes in the laxity/strength of the pelvic floor may contribute to stress incontinence. Stress incontinence is characterized by the involuntary leaking of urine during stress or increases in abdominal and bladder pressure, such as coughing and sneezing. Bladder pressure at these times exceeds urethral pressure, allowing urine to leak through the urethra.

Treatments for stress incontinence include pelvic floor exercises. By repeatedly contracting and relaxing the vagina and pelvic floor, leaking may decrease. In this patient's case, treating her cough with cough suppressants may additionally help with the urine leaks. In obese patients, 5 - 10% weight loss may also improve symptoms. Pessaries may be inserted into the vagina to increase urethral support. Urethral support can also be increased surgically by inserting a fascial sling or vaginal tape to support the urethra.

Smoking cessation is laudable on many accounts. It may contribute to low birth weight in the baby and is risk factor for a variety of cardiovascular diseases in the mother. It is not currently considered a risk factor for incontinence.

Episiotomy may be a risk factor for fecal incontinence, but it is not a known risk for urinary incontinence.

Oxybutynin is an anticholinergic amine used in the treatment of neurogenic bladder and overactive bladder/urge incontinence. Reports of its use during pregnancy and lactation are not available (Micromedex).

Duloxetine is used in the management of stress incontinence. It is a reuptake inhibitor of serotonin and noradrenaline. Its use is not suggested in pregnancy because it is category C and may have teratogenic effects.
Correct answer:
Calcium oxalate

Explanation
Calcium oxalate stones are the most common type of renal stones or nephrolithiasis.

Nephrolithiasis is a common problem, affecting some 2 - 9% of the population.

Patients with nephrolithiasis are likely to have recurrent episodes. 40 - 50% of patients are likely to have recurrent stones after an episode of nephrolithiasis.

According to Pietrow, each of the following stone types is seen with the following frequency:

Calcium oxalate (70%)
Calcium phosphate (5 - 10%)
Uric acid (10%)
Struvite (magnesium ammonium phosphate) (15 - 20%)
Cystine (1%)
Crystals form in urine when the urine is supersaturated with crystal-forming solutes such as calcium, phosphate, and uric acid. Some patients overexcrete solutes; others drink inadequate amounts of fluids to keep solutes dissolved.

Stones also occur when the urine is infected with urea-splitting bacterium. Here, urea is broken down into ammonia and bicarbonate, which then forms ammonium hydroxide and bicarbonate, which are the components of struvite stones.

Struvite stones consist of a triple phosphate of calcium, magnesium, and ammonium.

Certain stone inhibitors, such as pyrophosphate, citrate, and magnesium, prevent crystal growth. In patients who have low levels of these inhibitors, stones are more likely to form.

Stone prevention focuses on adequate hydration and dietary moderation of foods likely to cause stones. Specifically, decreased sodium and dairy products are recommended for patients with calcium stones; decreased liver and purine rich foods are recommended for patients with uric acid stones; and decreased of nuts, chocolate, some vegetables (beets and spinach) is recommended for patients with oxalate stones. Citrate supplementation is used in patients with low levels of urinary citrate, a stone inhibitor. Thiazides may be used to treat hypocalciuria in patients who overexcrete calcium.
Correct answer:
Urologic surgeon for radical nephrectomy

Explanation
The most appropriate intervention for this patient is referral to a urologic surgeon for radical nephrectomy, which is the standard treatment for localized RCC. The nephrectomy serves to diagnose, stage, and treat the cancer.

A referral to a medical oncologist for traditional cytotoxic chemotherapy is not recommended, as RCC is refractory to traditional chemotherapies. Immunotherapy (interleukin or interferon) and antiangiogenic agents are considered a reasonable addition to nephrectomy in patients with metastatic RCC, but there is no current evidence suggesting this patient has metastatic disease.

RCC is considered a radiation-resistant tumor, so external beam radiation is rarely used as a primary treatment. Radiation may have a role in palliative treatment in special circumstances.

Referral to a urologist for a retrograde pyelogram would not address the RCC. This type of imaging allows visualization of the bladder, ureters, and pelvicalyceal collecting system by administering contrast through a catheter to flow up toward the kidneys. This type of imaging may be helpful in the diagnosis of urethral strictures, trauma, and reflux, but adds no additional information and certainly no treatment value for this patient with RCC.

A referral to hospice for palliative care only suggests there are no reasonable treatments for this patient and that he is expected to die within 6 months; however, 5-year survival rates are around 66% for stage I RCC.
Correct answer:
Suggest pelvic toning exercises

Explanation
This patient has symptoms of stress incontinence and should be initially prescribed pelvic toning exercises.

Stress incontinence is characterized by the involuntary leaking of urine during stress or increases in abdominal and bladder pressure such as coughing and sneezing. Bladder pressure at these times exceeds urethral pressure, allowing urine to leak through the urethra.

Stress incontinence is more common in women than men. Obesity, pregnancy, and vaginal births may increase the risk for stress incontinence. In such cases, the pelvic floor muscles may be insufficiently strong to support the urethra and overcome pressure of urine flowing from the bladder.

Treatments for stress incontinence include pelvic floor exercises. By repeatedly contracting and relaxing the vagina and pelvic floor 30 - 50 times/day, leaking may decrease. In obese patients, 5 - 10% weight loss may also improve symptoms. This patient has an acceptable body mass index of 22 (18.5-24.9 kg/m2), so weight loss won't necessarily help her symptoms. Pessaries may be inserted into the vagina to increase urethral support and help with symptoms. Urethral support can also be increased surgically by inserting a fascial sling or vaginal tape to support the urethra.

Since surgical interventions are invasive and may involve bleeding and infection risks, medical therapies should be attempted first.

Increasing the time interval between voids is not suggested. She will increase the volume of urine retained in the bladder and put herself at risk for a larger volume leak.

In urge incontinence, decreasing the time between voids (e.g., scheduling voids every 2 hours) is suggested in order to avoid leaks. This patient does not have urge symptoms, such as increased frequency, nocturnal incontinence, or the extreme sensation of a need to void.

There are no FDA approved medications for the treatment of stress incontinence. Anticholinergic medications block muscarinic receptors in the smooth muscle of the bladder and thus inhibit detrusor contraction. These medications are associated with moderate improvements in urgency, frequency, and urgency incontinence episodes.(11)

Duloxetine, a serotonin and noradrenaline reuptake inhibitor, not fluoxetine, may be used in the treatment of stress incontinence. In small studies, Duloxetine may also improve symptoms of stress incontinence.

β-3 Agonists are also available for treating urgency incontinence. Stimulation of the β-3 pathway promotes smooth muscle relaxation of the bladder to increase urine storage. There is only one medication, Mirabegron in this class, and it has shown efficacy in alleviation of urinary incontinence symptoms.(11)
Correct answer:
Perform kidney function tests

Explanation
The correct response is that you should perform kidney function tests.

Your patient has galactorrhea, amenorrhea, and signs and symptoms that suggest a renal insufficiency (fatigue, somnolence, easy bruising, peripheral edema); the insufficiency was probably caused by long-standing diabetes (diabetic retinopathy develops after a long history of diabetes). Chronic renal failure elevates prolactin by decreasing peripheral clearance of the hormone. Evaluation of hyperprolactinemia should include a review of medications, including estrogen therapy, and history of fertility or gonadal dysfunction. Elevated prolactin levels can result in secondary hypogonadism.

In general, signs and symptoms of hyperprolactinemia are due to either the excess hormone secretion (i.e., galactorrhea and amenorrhea) or local compression (e.g., new-onset or persistent headache, dizziness, visual changes, and vision loss). Since your patient has no signs of local compression, biochemical tests should be ordered before the imaging studies. Laboratory evaluation should include a repeat serum prolactin test, measurements of TSH and free T4, and a pregnancy test. If the results come back normal and if other diagnoses are excluded, the most likely diagnosis is a prolactinoma. A pituitary MRI should only be obtained in such cases.

Elevated prolactin levels can result in secondary hypogonadism. Serum testosterone levels should be checked in men with galactorrhea.

Visual field testing can be performed in individuals with specific visual complaints, especially loss or impairment of peripheral vision.
orrect answer:
Diabetes mellitus

Explanation The correct answer is diabetes mellitus since the presence of polyuria would indicate hyperglycemia and the associated erectile dysfunction and/or balanitis may be the only other presenting symptom or sign of diabetes mellitus in a male patient. Erectile dysfunction is a common vascular and neurological complication of diabetes and occurs in up to 75% of male diabetics. Elevated blood sugars result in autonomic neuropathy of the cavernous nerve of the penis so that erectile dysfunction serves as one of the earliest indications of neuropathy. Likewise, hyperglycemia results in microvascular damage to the dorsal and cavernous arteries, in the same way retinopathy, nephropathy, and neuropathy develop, further contributing to poor perfusion and erectile dysfunction. Hyperglycemia also results in the colonization of skin organisms, commonly Candida, resulting in typical superficial yeast infections seen in diabetics such as balanitis in men and vulvovaginitis in women.
Benign prostatic hypertrophy (BPH) typically occurs in the periurethral zone of the prostate and usually presents with lower urinary symptoms (LUTS) that suggest obstruction (i.e. hesitancy, weak stream, straining, post-void leaking) or irritation (i.e. nocturia, frequency, urgency). Digital rectal examination of prostatic hyperplasia typically reveals a smooth, firm enlargement of the gland which may be asymmetrical or indurated. Early BPH is not typically associated with erectile dysfunction or Candidaskin infections.

Prostate cancer most often develops in the peripheral zone of the prostate and is usually asymptomatic. Locally advanced prostate cancer may encroach on the central transition zone of the prostate and present with irritative urinary symptoms. Prostate cancer that extends outside the prostate capsule may result in erectile dysfunction. Carcinomas in the peripheral zone are often palpable and typically a hard, irregular nodule or induration. Prostate cancer is not typically associated with Candidaskin infections.

Hypogonadism may present with fatigue, decreased libido, diminished erections, gynecomastia, or decreased testicular size, muscle mass, or hair growth associated with secondary sexual characteristics. It is typically not associated with an enlargement of the prostate, urinary complaints, or Candidaskin infections.

The characteristic presentation of diabetes insipidus (DI) is abnormally large amounts of dilute urine - insipidus means tasteless. Polyuria is massive, often associated with nocturia and enuresis, and results in dehydration, which is often not evident due to a compensatory increase in thirst and polydipsia. DI is the result of the posterior pituitary's failure to secrete antidiuretic hormone (ADH) resulting in central diabetes insipidus (DI) or the kidney's resistance to ADH resulting in nephrogenic DI. DI is not typically associated with Candidaskin infections.

References:
Correct answer:
Acute prostatitis

Explanation
Acute prostatitis is defined as an inflammation of the prostate gland that develops suddenly and is common in men, likely due to reflux of infected urine into intraprostatic ducts. This can happen after instrumentation, catheterization, or trauma, like horseback riding, biking, etc., and worsened by dehydration, as in this patient. The National Institutes of Health classification of inflammatory conditions of the prostate is as follows:


I Acute prostatitis
II Chronic bacterial prostatitis
III A Chronic prostatitis/pelvic pain syndrome, inflammatory
III B Chronic prostatitis/pelvic pain syndrome, noninflammatory
IV Asymptomatic inflammatory prostatitis
Gram negative organisms are the main culprit, including E.coli, proteus, klebsiella, enterobacter, and pseudomonas. Symptoms of dysuria, fever, perineal pain, and tender prostate are typical. Treatment is with trimethoprim-sulfamethoxazole or quinolones for 4 weeks. In sicker patients, hospitalization may be needed, in which case IV antibiotics with aminoglycoside and ampicillin should be given until the patient is afebrile for 24-48 hours, then oral antibiotics continued for total of 4-6 weeks to avoid complications such as abscess formation or chronic prostatitis.
Acute pyelonephritis presents with fever, flank pain, tender renal angle, and normal rectal exam. Treatment includes oral fluoroquinolone or trimethoprim-sulfamethoxazole for mild to moderate disease and IV ceftriaxone or a fluoroquinolone for hospitalized patients, to be substituted with oral antibiotics after improvement in symptoms. Total duration of antibiotics should be 10-14 days.

Acute urethritis is associated with dysuria and urethral discharge with pruritus at urethral meatus. Fever, chills, frequency, urgency, and hematuria are uncommon. It may be gonococcal, which is the most common cause of urethritis in men or nongonococcal urethritis (NGU). Although most cases of NGU are due to chlamydia trachomatis, other etiologies include T. vaginalis, Mycoplasma genitalium, and Ureaplasma urealyticum. Gram stain and culture or the urethral discharge should be done. Treatment is with ceftriaxone 125mg IM, cefixime 400mg PO, ciprofloxacin 500mg PO, or ofloxacin 400mg PO, all in a single dose in gonococcal urethritis and azithromycin 1gm PO or doxycycline 100mg BID for 7 days or ofloxacin 400mg PO BID for 7 days for NGU.

Rectal abscess is a distant possibility in this patient. It presents with constant pain in the rectal area and perhaps fever and malaise but no dysuria or cloudy urine. Rectal exam will be tender and reveal a fluctuant mass. UA, however, will not be abnormal. Treatment is with incision, drainage, and perhaps antibiotics for anaerobic coverage.

Anal fissure presents with excruciating pain with the passage of bowel movements and is associated with constipation. The passage of stool may be accompanied by bright rectal bleeding usually limited to a small amount on the toilet paper but sometimes more profuse bleeding. Treatment aims at relaxing the sphincter, keeping bowel movements soft and smooth, and pain control.
Correct answer:
Renal tubular obstruction

Explanation
Acyclovir precipitates in renal tubules because it is poorly soluble in urine. In that way, it causes the obstruction of renal tubules and acute renal failure.

Endothelial injury is characterized by reduced vasodilation, a proinflammatory state, and prothrombic properties; it may be associated with hypertension and diabetes, particularly in type 2 diabetes with insulin resistance. But in a patient with acute kidney failure who has been exposed to the high dose of parenteral therapy with a poorly soluble nephrotoxic drug, endothelial injury should not be your initial choice.

Renal tubular cell dysfunction caused by a hypersensitivity reaction to drugs or by infection will cause acute interstitial nephritis. It is often associated with obstruction or reflux, so you can include this on your list of differential diagnoses, but the development of acute renal failure during the therapy with acyclovir makes renal tubular obstruction more likely.

In acute interstitial nephritis, renal tubular cells dysfunction is caused primarily by a hypersensitivity reaction. When caused by an allergic reaction, the symptoms of acute tubulointerstitial nephritis are fever, rash, and enlarged kidneys. Besides, acyclovir-induced crystalluria that causes mechanical tubular obstruction is the better option in this case.

Kidney infection with acute renal failure is not a probable diagnosis in a patient that has no back pain and no signs of a urinary tract infection.
Correct answer:
A prostate-specific antigen test

Explanation
A prostate-specific antigen (PSA) test is correct. The patient presents symptoms of enlarged prostate, a common occurrence in a man of his age. His symptoms started several months before the visit, and they clearly bothered and irritated him. He does not present with symptoms of infection. The level of PSA, a marker of prostate cancer, is known to correlate well with the prostate's volume. Although most localized prostate cancers are discovered through PSA screening, active surveillance rather than immediate surgery, radiotherapy, or hormone treatment is now recommended.

The answer a serum creatinine test is incorrect.A creatinine test determines the level of creatinine, a substance that is normally eliminated by the kidneys. The amount of creatinine in the blood is an indicator of how well the kidneys work. This patient presents clear symptoms of an enlarged prostate, so this test, even though one of the basic check-up tests, is not a priority for good diagnosis in the case of this patient.

The answer a post-void residual urine test is not correct. This test measures the amount of urine left in the bladder after urination and can help evaluate an enlarged prostate; however, the PSA test is preferred, as it can give additional information on the health status of the patient. The patient is an elderly man, and the PSA test also provides a way to detect the presence of prostate cancer, a disease more frequently found in the elderly.

The answer a urine culture test is incorrect. The patient does not have symptoms of a urinary tract infection. He has no fever and does not experience sensations of burning or pain while urinating.

The answer a blood urea nitrogen test (BUN test)is incorrect. This test measures how much urea nitrogen is in the blood, and it is frequently performed with other tests to monitor or diagnose kidney dysfunction. This patient does not show any symptoms associated with kidney disease, but shows signs of an enlarged prostate problem.
Correct answer:
Acute interstitial nephritis

Explanation
This patient most likely has acute interstitial nephritis(AIN) secondary to his tetracycline exposure.

AIN is an immune-mediated form of acute kidney injury (acute renal failure).

Patients develop varying degrees of renal failure, characterized by changes in urine output, electrolyte imbalances, acidemia, and azotemia (elevations in serum creatinine with or without nausea, sleep disturbances, shakiness, etc.) in response to viral, bacterial, immunological, or pharmaceutical insults. Hypersensitivity reactions to the above exposures lead to tubulointerstitial Inflammation in AIN. Elevations In blood eosinophils and pyuria follow. White blood cell casts may be seen in the urine, as well as a small amount of hematuria and proteinuria (<1.5 g/d-2 g/day).

Some 5 - 15% of cases of acute kidney injury occur secondary to acute interstitial nephritis.

AIN is often diagnosed based on history of renal failure and urine findings 2 weeks after exposure to a new medication or a viral or bacterial infection. It may occur earlier in patients previously sensitized to the offending medication. A variety of antibiotics, ACE inhibitors, proton pump inhibitors, seizure medications, etc., are known to cause AIN. The development of AIN is not dependent on the size of the dose of the medication given. Many infections, including HIV, EBV and mumps, can also cause AIN; additionally, immunological diseases, such as lupus and Wegener's granulomatosis, can cause AIN.

AIN is treated by removing the offending medication and avoiding its future use.

If AIN occurred in the setting of an infection, or immunologic or neoplastic process, that disease should be treated.

Acute glomerulonephritis is a form of acute kidney injury in which glomeruli are inflamed and irritated, usually due to infectious or immunologic processes.

Azotemia, (see above) hematuria, and red blood cell casts are noted, which were not seen in this patient.

Acute tubular necrosis (ATN) is a form of acute kidney injury in which the renal tubules are directly affected. Contrast and cisplatin are 2 toxins known to cause ATN. Damaged tubules slough cells into the filtrate, giving urine a dark appearance; 'muddy brown casts' are seen in the urine. No such casts were noted here.

Acute urinary obstruction is a form of acute injury caused by the inability to clear urine (and hence all wastes cleared by the kidneys) from the body. Acute obstruction, with associated hydronephrosis, should be noted on renal ultrasound. It was not noted in this case.

Pyelonephritis is an infection of the kidney. Patients may present with fever, flank tenderness, nausea and decreased urinary output. White cell urine casts and bacteria may be noted in the urine. Patients often appear more ill than this patient did. Additionally, there was no bacterial growth noted in his urine.
Correct answer:
Quantitative cultures of urine

Explanation
Sepsis is a state caused by the infection that manifest as disruptions in heart rate, respiratory rate, temperature, and WBC. When it worsens to the point of end-organ dysfunction (renal, liver dysfunction, brain, or heart), then it is called severe sepsis. Once severe sepsis worsens to the point where blood pressure can no longer be maintained with intravenous fluids alone, then it is called septic shock. Therefore, your patient most probably has septic shock due to the urosepsis. The most common cause of urosepsis is obstruction. Patients at higher risk are elderly patients, diabetics, and immuno-suppressed patients. The diagnosis of urogenital tract infection can be established with absolute certainty only by quantitative cultures of urine. A positive urine culture confirms, but is not diagnostic of, symptomatic urinary infection. A negative urine culture, however, has a high negative predictive value and is useful for excluding urinary infection. Quantitative cultures of urine will also show what the causative agent is and determine the antibiotic therapy.

Your patient has symptoms of septic shock due to urosepsis, and only some patients with severe urosepsis may develop bacteremia. Blood culture is useful, but urine culture is both more specific and more sensitive in urosepsis.

Plain abdominal radiograph will show the presence and extent of calcification and calculi within the kidney or urinary tract. It is of help in monitoring change in position, increase in size, or number of renal stones, but it will not contribute to your management at this point.

Ultrasound scan can define kidney size, identify renal scars, and help in the evaluation of prostate gland and various complications of acute pyelonephritis, but the first and best step in diagnosis of urosepsis is to find the causative agent in the urine.
Correct answer:
Leuprolide (Lupron Depot)

Explanation
This patient is demonstrating manifestations suggestive of metastatic prostate cancer, suggested on the x-ray as extensive sclerotic areas throughout the pelvis and femur. Androgen deprivation is considered the primary approach to the treatment of metastatic prostate cancer. However, this approach has been found to be palliative, not curative. The goals of pharmacotherapy for prostate cancer are to induce remission, reduce morbidity, and prevent complications

GnRH agonists provide medical castration in patients with prostate cancer. They are used early and late in the course of the disease.

GnRH agonists bind to the GnRH receptors on pituitary gonadotropin-producing cells, causing an initial release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) and consequently a rise in testosterone levels for a few weeks. However, sustained use of these agents causes a decrease in the production of LH and FSH, which in turn leads to a decrease in testosterone production in the testes, reducing testosterone to castrate levels or to below the castrate threshold (50 ng/dL).

Leuprolide, a GnRH agonist, is indicated as a palliative treatment for advanced prostate cancer when orchiectomy or estrogen administration is not indicated or is unacceptable to the patient. It is a potent inhibitor of gonadotropin secretion when given continuously in therapeutic doses.

Antimicrotubule chemotherapy agents such as docetaxel and cabazitaxel have demonstrated improvements in overall survival in patients with metastatic, castrate-resistant prostate cancer. Docetaxel is indicated in combination with prednisone for the treatment of patients with androgen-independent (hormone-refractory), metastatic prostate cancer.

Antifungal agents such as ketoconazole produce a response similar to that of antiandrogens. These agents provide an alternative option that may produce clinical benefit if initial androgen deprivation therapy fails. These agents inhibit various cytochrome P-450 enzymes, including 11-beta-hydroxylase and 17-alpha-hydroxylase, which in turn inhibit steroid synthesis.

Proscar (finasteride) is a 5-alpha-reductase inhibitor. It inhibits this intracellular enzyme that converts the androgen testosterone into 5α-dihydrotestosterone (DHT). It is indicated for the treatment of symptomatic benign prostatic hyperplasia (BPH) in men.

Rapaflo (silodosin) is an alpha-adrenergic antagonist used in the treatment of BPH.
Correct answer:
Hydrocele

Explanation
A testicular mass that transilluminates in an infant is most likely a hydrocele. Hydroceles are common in infants and are formed when the processus vaginalis, a tubular extension of the peritoneum, fails to close during development. The processus vaginalis precedes the testes in their descent into the scrotum and then usually closes around the time of birth; however, 80-94% of newborns have a patent processus vaginalis, making hydroceles extremely common. When it does not close, peritoneal fluid collects in the tunica vaginalis, which surrounds the testes, creating enlargement of the scrotum that transilluminates on exam.

Inguinal hernias, especially indirect inguinal hernias, develop in a manner similar to hydroceles. The main difference is that the processus vaginalis is patent enough to allow bowel to pass through, not just peritoneal fluid; therefore, it would not transilluminate on exam.

Spermatoceles, also known as epididymal cysts, are cysts located at the head of the epididymis. They can present as transilluminating masses on exam; however, they are not nearly as common as hydroceles in infants, and they can be palpated as distinct from the testes on examination.

Testicular tumors are uncommon in infants; however, they are the most common solid tumors in males ages 15-35. A tumor would not be expected to transilluminate.

Varicoceles are dilated, tortuous veins surrounding the spermatic cord. They are sometimes found in adolescents but are rare in infants.
Correct answer:
Chronic renal disease

Explanation
The correct response is chronic renal disease. Casts are cylindrical structures, consisting of clumps or clusters of cells or material that can form in the renal distal and collecting tubules of the kidney. Casts form when the pH of the urine is acidic and when the urine is very concentrated. Casts dislodge from the kidney and can be seen in the urine. In order to see casts, urine must be visualized under low power on a microscope. There are various types of casts that can be characterized into acellular versus cellular casts; each category can be further characterized, and the various casts can be associated with various disease processes. Granular casts are the 2nd most common type of cast and result from the breakdown of cellular material. They are most often indicative of chronic renal disease, but can also be seen if a patient has just vigorously exercised. Waxy casts are also indicative of advanced renal disease, specifically indicating a more chronic issue.

Fatty casts are the result of the breakdown of lipid-rich epithelial cells; they are pathognomonic for high urinary protein nephrotic syndrome. High urinary protein nephrotic syndrome does not lead to the formation of granular casts.

Nephritic syndromes, urinary tract injury, glomerulonephritis, and vasculitis can all result in red blood cell casts. Whenever there are red blood cells within a cast, there is a strong indication for glomerular damage from a number of different disease processes. Glomerulonephritis does not lead to the formation of granular casts.
Correct answer:
Increased glomerular filtration

Explanation
This patient most likely is polyuric due to her increased blood volume and the increased glomerular filtration rate that occurs during pregnancy; both findings are normal.

This patient is not isosthenuric (specific gravity of urine = specific gravity of plasma). If she were, she could not concentrate or dilute her urine. Concentrating and diluting abilities are maintained in pregnancy. Isosthenuria occurs when tubules are diseased, such as in diabetic and other forms of chronic kidney disease, and may lead to polyuria, nocturia, and electrolyte imbalances.

This patient has trace glucosuria, which is likely due to high glomerular filtrate rates and less efficient tubular glucose absorption. Glucosuria is common in pregnancy and may certainly occur without diabetes. Her fingerstick glucose is not suggestive of diabetes.

Physiologic hydronephrosis occurs in pregnancy due to the high hormone levels (estrogen and progesterone) that dilate the ureters. Hydronephrosis may occur with or without obstruction, and obstruction may occur with or without hydronephrosis. Ureteral obstruction should be noted on ultrasound and may cause an increase in serum creatinine, which is not noted here.

Obstruction of the bladder or urethra may present with difficulty initiating voiding, incomplete emptying, and urinary frequency, dribbling, etc. Bladder obstruction may occur secondary to bladder stones or prostatic enlargement impeding flow through the urethra. The upper tract (proximal to the urinary bladder) may also become obstructed. Tumors, gastrointestinal processes, and retroperitoneal fibrosis (to name a few causes) may compress and obstruct the ureters.

Functional problems, such as diabetes, neurological injuries, and medications, may impair the bladder's ability to empty urine. Neurogenic bladder is diagnosed by cystometry, which demonstrates impaired bladder emptying and low pressures. It is suspected in patients with neuropathies (diabetes), neurological diseases (multiple sclerosis), and in patients who take medications that impair cholinergic stimuli for bladder emptying (cold medicines).

Additional causes of polyuria may include urinary tract infections (UTIs), which should be treated so that they do not affect the growing fetus.
Correct answer:
Klinefelter syndrome

Explanation
Fragile X syndrome results from a mutation in the FMR1 gene, located on the long arm of the X chromosome (Xq27). It is characterized by moderate intellectual disability. The phenotypic manifestations of fragile X syndrome vary, but often include developmental delay, hyperactivity, abnormal craniofacials, and macro-orchidism (in post-pubertal males). Greater than 99% of affected individuals have what is known as a "full mutation" in the FMR1 gene. This mutation is caused by an increased number of CGG trinucleotide repeats in the 5' end of the gene (> 230 CGG repeats), which causes aberrant methylation of the gene, and aberrant expression of the gene product. Mothers of affected children that have this full mutation are obligate carriers of a "premutation" in the FMR1 gene. This premutation or "intermediate" allele has between 55 and 230 CGG repeats, and can expand upon transmission to offspring. (The normal allele has between 6 and 54 CGG repeats). These women, and their family members, are at an increased risk to have children affected with fragile X syndrome. Molecular genetic testing is available on a clinical basis to determine the status of the FMR1 gene allele(s).

Klinefelter syndrome affects males. It is diagnosed by an abnormal karyotype. Individuals with this syndrome have an extra X chromosome, with the karyotype being 47, XXY (Variations occur, but this karyotype is the most common). The extra X chromosome seems to affect the functioning of the testes and testosterone production. Adolescent boys with this disorder may undergo gynecomastia. Most are tall, but not particularly coordinated. The penis is of normal length; however the testes are small. Treatment with male sex hormones can be helpful.

X-linked adrenoleukodystrophy is caused by a mutation in the ALD gene, located on the long arm of the X chromosome (Xq28). The childhood form most commonly presents between the ages of four and eight years. It begins with symptoms of attention deficit and hyperactivity disorder, but gets progressively worse, with symptoms including difficulty with previously mastered subjects such as speech and reading. The affected individual also becomes clumsy and has visual disturbances. Brain MRI is often abnormal, even while symptoms are still mild. The rate of progression of the disorder varies, but leads to death in a matter of years. Along with the childhood form of the disease, there are several other types. Type two usually presents during middle age (possibly as early as in the twenties), and includes leg stiffness and weakness and sexual dysfunction. This, too, is progressive, usually over decades. Type three, which is found in approximately 10% of cases, is characterized by adrenal insufficiency. Presentation can be anywhere between two years of age to adulthood.

X-linked mental retardation hypotonic facies syndrome is caused by a mutation in the XNP gene, also located on the X chromosome (Xq13.3). Affected individuals have a distinct phenotype that includes genital abnormalities, a common set of facial features, and severe developmental delays with intellectual disability. All patients have a normal 46, XY karyotype; however their appearance at birth can range anywhere from a male with hypospadius to a normal appearing female. Common craniofacial features include a small head circumference, small triangular nose, tented upper lip, prominent lower lip and open mouth. Short stature is common. Developmentally, milestones are delayed to a marked degree. Hypotonia is commonly present. Interestingly, the mutated gene appears to down regulate expression of the alpha-globin gene, leading to a microcytic and hypochromic anemia in some affected individuals.

Individuals with XYY syndrome have an abnormal karyotype - 47, XYY
Correct answer:
Stress incontinence

Explanation
This woman most likely has stress incontinence. Stress incontinence is characterized by the involuntary leaking of urine during stress or increases in abdominal and bladder pressure, such as coughing and sneezing. Bladder pressure at these times exceeds urethral pressure, allowing urine to leak through the urethra.

Stress incontinence is more common in women than men. Obesity, pregnancy, and vaginal births may increase the risk for stress incontinence. In such cases, the pelvic floor muscles may be insufficiently strong to support the urethra and overcome pressure of urine flowing from the bladder.

Treatments for stress incontinence include pelvic floor exercises. By repeatedly contracting and relaxing the vagina and pelvic floor, leaking may decrease. In this patient's case, treating her cough with cough suppressants may additionally help with the urine leaks. In obese patients, 5 - 10% weight loss may also improve symptoms. Pessaries may be inserted into the vagina to increase urethral support. Urethral support can also be increased surgically by inserting a fascial sling or vaginal tape to support the urethra. Duloxetine, a serotonin and noradrenaline reuptake inhibitor, may also improve symptoms of urinary stress incontinence.

In cases of urge incontinence, patients typically have involuntary leaks, increased urinary frequency, and nocturnal incontinence; they occur either during or just after the sensation of needing to void. Bladder detrusor muscles may have variable activity. Treatments include scheduled voiding and anticholinergic medications (oxybutynin, etc.).

Mixed incontinence refers to the presence of symptoms of both stress and urge incontinence. It may be seen in 1/3 of patients.

Overflow incontinence refers to urinary leaks that occur due to an obstruction of urine flow. Post-void residuals are typically elevated; normal post-void residuals in the absence of retention are less than 200 ml. Initially, patients may experience dribbling after voids, straining, the sensation of a full bladder, and a constant urge to void. Prostatic hypertrophy, atonic bladders, etc., can impede urine flow. Once urine volume exceeds bladder capacity, it may spill out, causing a leak. Overflow incontinence may be distinguished from urge incontinence by urodynamic testing, and it may be treated with terazosin and finasteride.

Incontinence may be a symptom of a urinary tract infection. In this case, the lack of fever, urinary white cells, urinary nitrate, and urinary leukocyte esterase make this diagnosis unlikely.
Correct answer:
Obesity-related glomerular disease

Explanation
Given the lack of findings to support alternate diagnoses, obesity-related glomerular disease is the most likely cause of this patient's proteinuria.

Obesity is an increasingly recognized modifiable risk factor for progressive kidney disease. The risk for developing progressive renal failure increases incrementally with increasing body mass index. Patients with a BMI >40 kg/m2 have an approximately 7-fold increased risk of developing progressive renal failure compared to the non-obese (<30 kg/m2) population. An increased BMI poses a risk for renal failure, even in patients without diabetes and hypertension.

In obese patients, a fixed number of nephrons are challenged to process the fluids and nutrients of an increased body mass. They respond by hyperfiltering, increasing glomerular volume, decreasing podocyte number/density, and eventually leading to obesity-related glomerulopathy (proteinuria, elevated serum creatinine) and/or obesity-related glomerular scarring (glomerular sclerosis, proteinuria).

Weight loss of even 5 - 10% can significantly improve a patient's risk factors for obesity-associated disease. Given her severely elevated BMI, a gastric surgical procedure is likely indicated. A BMI >40 kg/m2 is an indication for such procedures.

Diabetic kidney disease is a well-known cause of renal failure; it is one of the leading causes of end-stage renal disease in the United States. This patient does not meet the criteria for diabetes (e.g., fasting glucose >126 mg/dL, random glucose >200 mg/dL); she also has no glycosuria. Although microvascular disease may precede the diagnosis of diabetes, no diabetic changes were noted on her retinal exam.

Membranoproliferative renal disease typically presents with proteinuria and hematuria.

Hypertensive nephrosclerosis is also a very common cause of progressive kidney failure in the United States, but is an unlikely cause of this patient's proteinuria. It occurs at 2 - 3 times the rate in patients with consistently elevated pressures (150 - 160/80 mm Hg) than in patients with pressures in the 130 - 140/80 mm Hg range. This patient's current pressure is 135/78 mm Hg. If her pressure were consistently at this level, she would be prehypertensive. Knowing that her creatinine is elevated and that she has proteinuria, a more desirable pressure would be in the 120 - 130/70 - 80 mm Hg range in order to best prevent progressive renal function loss. In some cases, hypocomplementemia, positive hepatitis titers, and/or positive antineutrophil antibodies are also noted. The lack of these findings makes this diagnosis unlikely.

Tubular disease may lead to low levels of proteinuria; compared to glomerular disease, much lower levels of protein are found in the urine. Also expected in tubular disease would be some electrolyte or acid-base dysfunction since the tubules are key in regulating acid-base and mineral reabsorption and excretion. The normal urine pH, serum bicarbonate, serum chloride, serum potassium, serum calcium, and phosphorus make this a less likely diagnosis.
Correct answer:
Anti-DNase B serology

Explanation
The correct answer is anti-DNase B serology to identify post-streptococcal glomerulonephritis. Group A β-hemolytic streptococci pharyngitis may result in the delayed complication of post-streptococcal glomerulonephritis 10-14 days after the infection. Patient presentations may range from subclinical symptoms to acute nephritic syndrome as streptococci may produce streptolysin, DNase, and hyaluronidase that lead to tissue destruction and disseminate infection. Serology testing to identify antibodies to these exoenzymes can aid in the diagnosis by demonstrating indirect evidence of infection. Confirmation may require serial antibody draws that reveal a rise in titer levels above the baseline.

Urine culture and sensitivity would be appropriate if the clinical picture only entailed fever and flank tenderness in the presence of pyuria and hematuria, suggesting a urinary tract infection. That diagnosis does not explain the presence of proteinuria with renal tubular epithelial cells and casts. These indicate intrinsic kidney damage, which is not seen in urinary tract infections. Further serology testing is indicated in the post pharyngitis period.

Urine cytology is ordered in the presence of gross or microscopic hematuria, which is often painless, to identify malignant cells in the urinary tract. This patient does not fit the epidemiologic profile or clinical presentation of malignancy to warrant cytology testing.

Erythrocyte sedimentation rate can aid in detecting an inflammatory response, such as nephritis, but it lacks specificity to identify the infectious process.

Urine protein electrophoresis is indicated to identify abnormal levels of free monoclonal light chains (Bence Jones protein) from immunoglobulins in cases of myeloma.



References
Correct answer:
Sodium Pentosanpolysulfate (Elmiron) 100mg TID

Explanation
The scenario is describing a patient with interstitial cystitis (IC). Patients with IC have a 10:1 female to male ratio and are typically in the third decade of life. Symptoms usually include urinary frequency, nocturia, urgency, and bladder or pelvic pain. Physical examination is usually unremarkable and helpful at ruling out other causes of the patient's symptoms. The urinalysis and urine culture are usually unremarkable, which also rules out other differential diagnoses. Cystoscopy with hydrodistention under sedation is often used to diagnose IC by both the appearance of the bladder and the bladder capacity (not usually over 350cc). Hunner's ulcers seen during cystoscopy with hydrodistention are pathognomonic for interstitial cystitis, although they do not have to be present for a patient to have this diagnosis (only present in 5-10% of cases). The hydrodistention can also help to relieve symptoms, and can be an effective treatment for many patients with IC. However, if symptoms persist, then other treatment options are warranted. Altering diet and avoiding foods and beverages that are bladder irritants can be helpful in improving symptoms in patients with IC. Beyond these measures, there are various medications that can offer relief.

Elmiron stands alone in its class of medications, but is similar to a class of medications called low molecular weight heparins. It prevents the irritation of the bladder wall that is the cause behind the patient's symptoms. This medication is prescribed 100mg TID and is a first-line treatment. It is the best choice of those listed as potential answers.

Ciprofloxacin (Cipro) is an antibiotic commonly used to treat urinary tract infections (UTI). While UTI would have been high on the list of differential diagnoses for this patient, it was ruled out by the negative urinalysis and urine culture.

Bisacodyl (Dulcolax) is a medication commonly used to treat constipation and would therefore not be an appropriate treatment for this patient.

Hydrocodone (Vicodin) and acetaminophen/aspirin/caffeine (Excedrin) are both commonly used to treat pain. Hydrocodone is often prescribed to patients with IC, as chronic opioid use is not uncommon due to the occasional extreme nature of the pelvic pain. However, it would not be the next best treatment and is essentially masking symptoms and not treating the IC. Excedrin is a pain reliever, but it contains caffeine. Caffeine is a bladder irritant and should be avoided by patients with IC, as it can potentiate the symptoms.

References:
Correct answer:
ACE inhibitor

Explanation
The pediatric patient described is apparently suffering from nephrotic syndrome. Glomerular disease induced proteinuria is the most common cause of nephrotic syndrome in children due to damage to the glomerular filtration barrier resulting in leakage of plasma proteins into the glomerular ultrafiltrate. Signs and symptoms in children include edema, urine protein: creatinine ratio > 0.2/mg creatinine; heavy proteinuria (urine protein >40 mg/m2/hr), hypoalbuminemia, and hyperlipidemia. The nephrotic range of proteinuria in children is higher than in adults (> 40 mg/m2/hr). Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers not only lower blood pressure but have that additional benefit of slowing the progression of kidney disease even in patients with normal blood pressure. Although this child is normotensive and is already receiving steroid treatment, the next best additional treatment, therefore, is an ACE inhibitor or an angiotensin receptor blocker (ARB) to decrease the proteinuria and GFR decline in order to reduce the risk of chronic kidney disease.

Diuretic is incorrect. Although a diuretic would provide symptomatic relief for the edema, it would not prevent the development of chronic kidney disease in this patient.

Spironolactone is incorrect. Spironolactone is an inhibitor of renal aldosterone effects such as sodium and water retention and would help combat the edema in this patient but would not decrease the risk of chronic kidney disease.

Beta blocker is incorrect. Beta blockers can be useful in the treatment of hypertension but this patient has not yet developed hypertension.

Mixed alpha and beta antagonist is incorrect. The use of a mixed alpha and beta antagonist drug is not indicated in this normotensive patient and would likely not reduce the risk of chronic kidney disease.
Correct answer:
Wilm's Tumor

Explanation
The clinical picture is suggestive of Wilm's Tumor. It accounts for most renal tumors in childhood during the first 5 years of life. It affects both sexes equally. It is a solitary growth that affects either part of the kidneys. There are congenital anomalies associated with it, most commonly the GUT anomalies, hemihypertrophy, sporadic aniridia, and intellectual disability. It is commonly manifested by an abdominal mass that is described as generally smooth, firm and rarely crosses the midline, and it causes abdominal pain and vomiting. Hypertension is seen in 60% of the patients either due to elaboration of renin by the tumor cells or due to compression of the renal vasculature by the tumor. Hematuria is also uncommon and mostly microscopic. CT scan confirms the diagnosis which will show an intrarenal tumor, therefore ruling out Neuroblastoma. Treatment is by surgical removal. Chemotherapy is indicated post-operatively for the residual tumor.

Neuroblastoma is a malignancy of the neural crest. It is the most common solid tumor in children outside the CNS. It is slightly more common in males and whites and median age of diagnosis is 2 years old. It arises mostly in the abdomen either in the adrenal gland or retroperitoneal sympathetic ganglia followed by the thoracic area mostly seen in the posterior mediastinum. Other sites are the head, neck, and epidural area. Tumors in the head and neck region are sometimes associated with Horner's Syndrome (Mioisis, Ptosis, Anhidrosis, and Enophthalmos). Diagnosis is by CT scan or MRI but pathologic diagnosis is made by biopsy. Tumor markers such as VMA and HVA (Homovanillic Acid) help confirm the diagnosis. Treatment is surgery, chemotherapy, and radiation depending on the stage of the tumor.

Nephroblastomatosis are immature renal elements called Nephrogenic rest. It is a Wilm's tumor precursor lesion that is both unifocal and deep within the Renal parenchyma (intralobar rest) or multi-focal (perilobar rest). Subsequent development of Wilm's tumor in the other kidney is more likely in patients with this feature; therefore prompt inspection of the contralateral kidney is necessary during surgery of the neprhogenic rest. CT scan follow-up should also be done.

Renal Cell Carcinoma is rare during the first decade of life but can occur occasionally in teenagers. Initial presentations are abdominal mass and hematuria. Surgical resection may offer cure, but prognosis is poor with post-operative residual disease.

Mesoblastic Nephroma is a massive, firm, solitary renal mass and is generally thought to be benign. It resembles Leiomyoma or low-grade leiomyosarcoma grossly and microscopically. It also accounts for the majority of congenital renal tumors. It is more often seen in males and noted to produce renin. Treatment is surgical resection.
Correct answer:
Renal biopsy

Explanation
This patient most likely has acute interstitial nephritis (AIN) secondary to her penicillin exposure. Of the listed choices, only renal biopsies yield information specific to acute interstitial nephritis.

Renal biopsy is the criterion standard for diagnosing AIN. Lymphocytic and plasma cell infiltrates in the peritubular areas of the interstitium are noted. However, being an invasive procedure, it is not used in all patients, especially if the condition is mild or if the patient improves rapidly after removing the offending cause.

Renal ultrasound may show slight increases in renal size and cortical echogenicity in AIN, but this may also occur with other renal conditions. A clinician may order this test to evaluate for other forms of injury (such as acute renal obstruction) in the evaluation of acute kidney injury.

24-hour urine samples are used to assess urine output, daily protein, electrolyte excretion, and creatinine clearance, a measure of renal filtering ability. Currently, calculations of creatinine clearance are made using the modification of diet in renal disease (MDRD) equation. Here, a 24-hour urine collection will tell us how well her kidneys are working, but it will not show the cause of their decline in function.

Elevated Urinary eosinophils may be found in a variety of other diseases, including pyelonephritis and prostatitis. The positive predictive value of urine eosinophils for diagnosing AIN is low (Kodner).

Gallium scans have limited predictive value for diagnosing AIN (Markowitz). Cortical necrosis (i.e., secondary to ischemia) unrelated to AIN and other diseases may cause similar patterns of uptake as AIN.

If the patient was still on the medication suspected to cause the problem, it should be discontinued and never again used. This alone may cause resolution of her illness in a couple of weeks. Her symptoms, urine output, volume status, serum creatinine, and electrolytes should be monitored to evaluate for the need for dialysis. She can be started on prednisone therapy for 2 weeks, to be tapered thereafter.
Correct answer:
Perform a red blood cell transfusion

Explanation
This patient's most likely diagnosis is acute renal failure or acute kidney injury (AKI) due to hypovolemia and prerenal causes.

The current treatment for AKI is mainly supportive in nature; no therapeutic modalities to date have shown efficacy in treating the condition. Maintenance of volume homeostasis and correction of biochemical abnormalities remain the primary goals of treatment. Supportive interventions include, as necessary, correction of fluid overload with furosemide; correction of severe acidosis with bicarbonate administration, which can be important as a bridge to dialysis; correction of hyperkalemia; correction of hematologic abnormalities (such as anemia, uremic platelet dysfunction) with measures such as transfusions; and administration of desmopressin or estrogens.

Dopamine in small doses (e.g., 1-5 mcg/kg/min) causes selective dilatation of the renal vasculature, enhancing renal perfusion. Dopamine also reduces sodium absorption; this enhances urine flow, which helps to prevent tubular cast obstruction. However, most clinical studies have failed to establish this beneficial role of low-dose dopamine infusion, and one study demonstrated that low-dose dopamine may worsen renal perfusion in patients with AKI.

Furosemide can be used to correct volume overload when patients are still responsive; this often requires high intravenous (IV) doses. Furosemide plays no role in converting an oliguric AKI to a nonoliguric AKI or in increasing urine output when a patient is not hypervolemic.

Dietary changes are an important element of AKI treatment. Restriction of salt and fluid becomes crucial in the management of oliguric renal failure, in which the kidneys do not adequately excrete either toxins or fluids. Because potassium and phosphorus are not excreted optimally in patients with AKI, blood levels of these electrolytes tend to be high. Restriction of these elements in the diet may be necessary, with guidance from frequent measurements.

Therapeutic agents (such as dopamine, nesiritide, fenoldopam, mannitol) are not indicated in the management of AKI and may be harmful for the patient. All nephrotoxic agents (e.g., radiocontrast agents, antibiotics with nephrotoxic potential, heavy metal preparations, cancer chemotherapeutic agents, nonsteroidal anti-inflammatory drugs [NSAIDs]) should be avoided or used with extreme caution. Similarly, all medications cleared by renal excretion should be avoided, or their doses should be adjusted appropriately.
Correct answer:
Chlamydia trachomatis

Explanation
Chlamydia are bacteria. Characteristic of chlamydia infections is the development of inclusion bodies. Chlamydia trachomatis cause 30-40% of all cases of nongonococcal urethritis in heterosexual males. Chlamydia trachomatis causes more nongonococcal urethritis in boys/men than Trichomonas vaginalis does.

Urethritis is an inflammation of the urethra. It is classified as either gonococcal urethritis (caused by Neisseria gonorrhoeae) or nongonococcal urethritis (caused by something other than Neisseria gonorrhoeae). Common causes of nongonococcal urethritis are Chlamydia trachomatis, Trichomonas vaginalis, and Ureaplasma urealyticum.

Chlamydophila psittaci does not cause nongonococcal urethritis. Chlamydophila psittaci causes a systemic illness called psittacosis, parrot fever, or ornithosis. Psittacosis is acquired from birds.

Trichomonas vaginalis is a protozoan. Trichomonas vaginalis can cause nongonococcal urethritis in males. It also causes trichomoniasis vaginitis, sometimes called trichomoniasis.

Ureaplasma urealyticum is considered a mycoplasma. Ureaplasma urealyticum is in the family Mycoplasmataceae and the genus Ureaplasma. Bacteria in the genus Ureaplasma require urea; therefore, Ureaplasma urealyticum is found primarily in the genitourinary tract. Ureaplasma urealyticum is a common cause of nongonococcal urethritis.

Pneumocystis jirovecii (formerly called Pneumocystis carinii) is a fungus, not a protozoan. In an immunosuppressed host, Pneumocystis jirovecii can cause pneumonia. Pneumocystis jirovecii does not cause nongonococcal urethritis.
Correct answer:
Obstructive uropathy

Explanation
This patient most likely has obstructive uropathy secondary to an enlarged prostate. His prostate is enlarged, and his post-void residual is elevated (>200 mL). Obstructive uropathy can occur from compression of any portion of the urinary tract. Lower tract obstruction includes obstruction of the bladder or urethra and may present with micturition problems such as difficulty initiating voiding, incomplete emptying, urinary frequency, dribbling, etc. Bladder obstruction may occur secondary to bladder stones or prostatic enlargement impeding flow through the urethra.

Neurogenic bladder is a functional impairment in bladder emptying that occurs in neurogenic diseases and as a complication of medications. It is diagnosed by cystometry and may be treated by using scheduled voids, self-catheterization, cholinergic agonists, and suprapubic catheterization if other treatments fail.

Prolonged acute obstruction and/or chronic obstruction may cause declining glomerular filtration rates, inability to concentrate urine, inability to properly acidify the urine, and dysfunctional sodium and potassium excretion. This patient had a normal urinalysis as well as normal serum sodium, potassium, and bicarbonate levels, suggesting that his obstructive uropathy did not lead to obstructive nephropathy.

Infectious cystitis and prostatitis may present with increased urinary frequency.

An enlarged prostate may be noted in prostatitis. Both would likely be accompanied by fever, pyuria, and leukocytosis, which are not noted in this vignette. Both cystitis and prostatitis are complications of prostatic enlargement.
orrect answer:
Streptococcus pyogenes (group A beta-hemolytic)

Explanation
Streptococcus pyogenes (group A beta-hemolytic) cause 3 types of diseases:

pyogenic diseases, such as pharyngitis and cellulitis
toxigenic diseases, such as scarlet fever and toxic shock syndrome
immunologic diseases, such as rheumatic fever and acute glomerulonephritis. Glomerulonephritis occurs especially following skin infections.
Streptococcus pneumoniae are gram-positive lancet-shaped cocci arranged in pairs (diplococci) or short chains. On blood agar, they produce alpha-hemolysis. Virulence factors of Pneumococci are polysaccharide capsules. Pneumococci cause pneumonia, bacteremia, meningitis, and infections of the upper respiratory tract, such as otitis and sinusitis. Mortality rate is high in elderly, immunocompromised (especially splenectomized), and/or debilitated patients. They should be immunized with the polyvalent polysaccharide vaccine.

Peptostreptococci grow under anaerobic or microaerophilic conditions and produce variable hemolysis. Peptostreptococci are members of the normal flora of the gut and female genital tract and participate in mixed anaerobic infections of the abdomen, pelvis, lungs, and brain.

Streptococcus agalactiae (group B streptococcus) colonize the genital tract of some women and can cause neonatal meningitis and sepsis. They are usually bacitracin-resistant.

Enterococcus faecalis (group D streptococcus), formerly known as Streptococcus faecalis, are part of the normal flora in the gut. They can cause urinary, biliary, and cardiovascular infections.
Correct answer:
Henoch-Scholein purpura

Explanation
The most likely diagnosis is Henoch-Scholein purpura, which is also known as anaphylactoid purpura. It is the most common cause of non-thrombocytopenic purpura in children. Boys are affected twice as frequently as girls. It is a common vasculitis of small vessels, with cutaneous and systemic manifestations. The systems primarily involved are the skin, gastrointestinal tract (GIT), and kidneys.

The characteristic manifestation of the disease is the rash, which presents initially as a pink maculopapular rash, but progresses to petechiae and purpura, often referred to as palpable purpura. The rash may continue to appear intermittently for 3 or 4 months, or even up to 1 year.

Edema and vasculitis of the GIT may lead to GI hemorrhage, manifesting with colicky pain in abdomen, vomiting, and hematemesis. There may be enlargement of mesenteric lymph nodes. Stool is positive for occult blood.

Swelling of knee and ankle joints is frequently seen due to serous effusion. There may be edema of the dependent areas. Renal involvement, which is the most important cause of morbidity and mortality, manifests as hematuria, proteinuria, and hypertension. Central nervous system and cardiac involvement may rarely occur.

Laboratory findings include thrombocytosis, leukocytosis, and elevated ESR. Serum IgA levels are elevated. Urine examination shows albuminuria, hematuria, and the presence of white blood cells and casts in the urine. Renal biopsy may show mesangial deposition of IgA.

Diagnostic criteria of Kawasaki disease are fever of more than 5 days duration and the presence of at least 4 of the following conditions:

(1) Strawberry tongue (protuberance of tongue papillae) suggestive of streptococcal infection
(2) Diffuse reddening of the oral and pharyngeal mucosa, dry and cracking lips.
(3) Conjunctivitis without any discharge.
(4) Edema/erythema of the hands and feet and later desquamation of the skin of the fingers and toes.
(5) Polymorphous rash.
(6) Cervical lymphadenopathy (at least one lymph node >1.5 cm).
These features are not present in the above child.

Systemic lupus erythematosis (SLE) is a multisystem disease involving nearly all the organs. It is an autoimmune disorder that causes inflammation of the blood vessels and connective tissue, resulting in multisystem involvement. It is seen more commonly in girls in contrast to Henoch-Schonlein purpura, which is more common in boys. Joints may be merely stiff or there may be active inflammation.

Cutaneous manifestations include malar, or butterfly, rash involving the cheeks and nasal bridge. Rash may be photosensitive and may involve all sun exposed areas. This rash is quite different from the rash of Henoch-Schonlein purpura. Hepatosplenomegaly and lymphadenopathy are often present.

Cardiac involvement may include pericarditis, valvular thickening, myocarditis, conduction abnormalities, and congestive cardiac failure. Pulmonary involvement includes pulmonary hemorrhage and fibrosis. This is in contrast to the index case. Renal involvement may manifest as hypertension, edema, electrolyte abnormalities, nephrosis, or acute renal failure.

Systemic onset juvenile rheumatoid arthritis (JRA) may be characterized by spiking fevers, arthritis, hepatosplenomegaly, lymphadenopathy, and serositis leading to pericardial effusion. Fever is accompanied by a faint transient, evanescent salmon-colored macular rash more commonly over the trunk and proximal limbs. It is non-pruritic and may last for a few hours. Heat, even that of a warm bath, may cause reappearance of the rash. Lab investigation includes raised ESR, leukocytosis, thrombocytosis, and C-reactive proteins (CRP) and anemia of chronic disease. JRA is the most common chronic rheumatologic disease in children, with a minimum duration of 6 weeks. The new nomenclature juvenile idiopathic arthritis (JIA) is being increasingly used to better define various subgroups.

Clinical manifestations of Polyarteritis nodosa (PAN) is a necrotizing vasculitis involving small and medium sized arteries. Boys and girls are equally affected. It is believed to be a post-infective autoimmune response in susceptible individuals commonly occurring after upper respiratory infection by group A streptococcal infection, chronic hepatitis B infection, infectious mononucleosis, and tuberculosis. Common features include fever, weight loss, and abdominal pain. Skin manifestations include purpura, edema, and painful nodules along the course of arteries. Cardiac involvement occurs as myocarditis, pericarditis, and arrhythmias. Angiography may show aneurismal dilatation and segmental stenosis.
Correct answer:
Bilateral ureteral stents and nephrostomy tubes

Explanation
This patient has bilateral hydronephrosis and an acute kidney injury resulting from a pelvic fracture, which is compressing and obstructing the most proximal part of both her ureters.

Until the fracture is repaired and the compression is relieved, only bilateral ureteral stents and nephrostomy tubes will assist in urine flow. Because of the complexity of the urinary system, more than one type of treatment may be required. A ureter stent, involves inserting a hollow tube inside the ureter to keep it open. Nephrostomy tubes are placed through your back to drain the kidney directly. Relief of urinary obstruction represents the most common indication for percutaneous nephrostomy placement, representing 85-90% of patients in several large series.

Her compression is proximal to the bladder, making all choices that bypass the bladder (suprapubic catheter, Foley catheter) ineffective.

Once the compression is relieved, hydronephrosis resolves and associated edema is diminished, the patient may void on her own. Diapers may not absorb the high urine outputs seen after obstruction, so they may not facilitate monitoring intake and output.

Intravenous fluids may be necessary for several reasons. The patient likely had little fluid input following her fall. Decreased effective circulating volumes may contribute to impaired glomerular filtration. After her obstruction is relieved, she will likely have large volume urine output and have high urine sodium losses as her tubules recover.

How completely her renal function will recover remains to be seen. Animals may recover <25-50% of glomerular function after such an obstruction. Close monitoring of serum creatinine, electrolytes, and urine output is critical in the days following obstruction. In the weeks and months afterwards, further recovery may be seen.
Correct answer:
Prescribe calcium supplements with meals

Explanation
This patient had a single episode of flank pain and hematuria, presumably due to oxalate-based kidney stones. She should be prescribed calcium supplements to be taken with meals.

Orlistat has been reported in association with calcium oxalate stones. Orlistat inhibits gastric and pancreatic lipase, leading to malabsorption of ingested fats and their elimination in the stool. These fats may bind calcium, leaving gastrointestinal oxalates unbound and available for reabsorption and deposition in the renal tubules.

In her workup for stones, a 24-hour urine showed increased levels of oxalate.

Hyperoxaluria can be treated by using calcium supplements with meals. Dietary calcium binds to oxalate and allows it to be eliminated in the stool. Primary hyperoxaluria is a genetic disorder whereby hepatic enzymes (alanine glyoxylate aminotransferase) are deficient and oxalate is produced in excess. Oxalate deposits in various organs, including the liver, kidneys, etc. Liver transplantation alone, or with renal transplantation, in patients with renal failure has successfully treated this disorder. Cholestyramine is also used to bind dietary oxalate.

Hypocitraturia can be a risk for renal stones because citrate inhibits stone formation; however, no hypocitraturia was noted, making the need to prescribe sodium citrate unnecessary. Excess sodium intake can exacerbate calcium-based stones by allowing for increased renal calcium excretion; therefore, sodium bicarbonate use is not advised in this patient. Bicarbonate supplements may further alkalinize the urine. Since calcium stones precipitate at high pH, bicarbonate supplements may exacerbate their formation.

Implementing a 1.1-liter daily fluid intake is likely insufficient for the prevention of stones. In most patients, urine is concentrated with this volume of intake; concentrated urine promotes stone formation.
Correct answer:
Prostate cancer

Explanation
This patient's presentation is most consistent with prostate cancer. Risks associated with prostate cancer include a high-fat diet, family history, and African American ethnicity. Upon digital rectal exam (DRE), it may manifest as focal nodules or areas of induration within the prostate. Obstructive voiding symptoms can occur with prostate cancer or benign prostatic hypertrophy; however, the prostate is more likely to demonstrate the absence of the median sulcus in BPH, not nodularity, as is observed in cancer. Manifestations of metastatic and advanced prostate cancer may also include weight loss and loss of appetite, anemia, bone pain (with or without pathologic fracture, most likely of the lumbar spine), neurologic deficits from spinal cord compression, and lower extremity lymphedema secondary to lymph node metastasis.

Acute bacterial prostatitis typically presents with fever, chills, malaise, arthralgias, myalgias, perineal or prostatic pain, dysuria, and obstructive and irritative urinary tract symptoms, including frequency, urgency, dysuria, nocturia, hesitancy, weak stream, and incomplete voiding. There may also be lower abdominal or back pain and spontaneous urethral discharge. The prostate will be tender, nodular, hot, boggy, or normal-feeling on digital rectal examination in acute prostatitis. Suprapubic abdominal tenderness and an enlarged tender bladder due to urinary retention may also be present. Absence of systemic symptoms and persistence of pain for at least 3 months indicates chronic prostatitis.

Risk factors that favor the development of bladder cancer include cigarette smoking and exposure to industrial dyes or solvents. Common presenting findings include gross or microscopic hematuria and irritative voiding symptoms such as frequency and urgency. Metastasis may cause hepatomegaly, lymphadenopathy, and lymphedema associated with involvement of pelvic lymph nodes.

A form of nephrolithiasis, ureterolithiasis is caused by calculi in the ureters. It presents as abrupt, severe, colicky pain in the flank and ipsilateral lower abdomen. There is often radiation to testicles or vulvar area with intense nausea with or without vomiting. There is significant costovertebral angle tenderness; pain can move to the upper/lower abdominal quadrant coinciding with the migration of the ureteral stone. Patients typically are constantly changing body positions, such as writhing and pacing about. Tachycardia, hypertension, and microscopic hematuria are common.
Correct answer:
Bladder cancer

Explanation
Hematuria is the most common presenting sign of urinary tract cancer, and bright red gross hematuria is usually of lower urinary tract origin. Silent or painless hematuria suggests tumor or renal parenchymal disease, so the clinical picture points to cancer, with bladder cancer as the most likely diagnosis. Smoking and exposure to industrial dyes or solvents (like in a rubber plant) are risk factors for bladder cancer. Bladder cancer is the second most common urologic cancer, and the mean age at diagnosis is 65. It is more common in men than women (2.7:1), and 98% of primary bladder cancers are epithelial malignancies (majority urothelial cell carcinomas). Ordering cytology of the urine sample is often helpful with higher grade and stage bladder cancers. Patients can become anemic with chronic blood loss, so a CBC is justified. Diagnosis is made by cystoscopy with biopsy.

Acute cystitis typically presents with irritating voiding symptoms (frequency, urgency, dysuria), suprapubic discomfort, and possible hematuria. Urinalysis will show pyuria, bacteriuria, and varying degrees of hematuria. Urine cultures will show specific organisms.

Renal cell carcinoma can present with flank pain, hematuria, persistent back pain, and an abdominal mass; also, it can be found incidentally on CT scan. RCC is more common in men than women (2:1), and it has a peak incidence in ages 50-60. This could be a possible option for diagnosis, but the significant history of smoking and previous work history points more toward bladder cancer.

Urethritis is inflammation of the urethra that presents with urethral discharge, dysuria, and itching. Urethritis is most often caused by an STD. This patient does not have a history of unprotected sexual intercourse or any other symptoms that would indicate this diagnosis.

Ureteral calculi can present with hematuria, but it also typically presents with flank or abdominal pain. If the stone is in the ureter, it often causes some hydroureter with or without hydronephrosis, both of which cause some pain or discomfort. The patient has no past history of forming stones.
Correct answer:
Acute pyelonephritis

Explanation
The symptoms of high fever with chills, nausea, vomiting, and back pain with tenderness in the renal angle are classic for pyelonephritis. It is a common condition in young women. The common organisms are gram negative, for example E.coli, klebsiella, proteus, enterobacter, and pseudomonas. Gram positive bacteria, like staphylococcus aureus and enterococcus fecalis, may also be seen. The usual mode of infection is ascent from the lower urinary tract, except for staphylococcus aureus, which is hematogenously spread. Leukocytosis with a left shift and abnormal urine with pyuria and bacteriuria confirm the condition. Absence of pyuria should be an indication to look for an alternative diagnosis. Hematuria may also be present. Blood and urine cultures should be done. Imaging may be needed in complicated cases, in which scenario an ultrasound may reveal hydronephrosis due to obstruction from a calculus or other causes. It is generally recommended that all males with acute pyelonephritis undergo imaging with ultrasound or CT scan, since such an infection is usually associated with an anatomical abnormality like enlarged prostate, etc. A long urethra and absence of organisms residing in vagina makes it unusual for men to have a urinary infection with a normal anatomy. Treatment should be started empirically without waiting for culture results, since they are usually not available immediately and, as they become available, antibiotics may be changed accordingly. Urine gram stain, which is available right away, may be a useful tool to direct antibiotic treatment. Indications for hospitalization include vomiting, pregnancy, HIV disease, diabetes, impending septic shock with unstable vitals, and other comorbidities like renal failure, post transplant, etc. It should be treated with oral fluoroquinolone or trimethoprim-sulfamethoxazole for mild to moderate disease and IV ceftriaxone or a fluoroquinolone for hospitalized patients, to be substituted with oral antibiotics after improvement in symptoms. Total duration of antibiotics should be 10-14 days. Prognosis is usually good if diagnosis is prompt, treatment appropriate, and complications absent.

Acute cystitis is a milder disease, which is more common in women than men due to a short urethra and proximity to vagina with its abundance of micro-organisms. About 50-60% adult women have had a urinary tract infection in their lives at some point. 10% postmenopausal women also have been found to get these infections. Coitus seems to be a predisposing factor, and symptoms quite often arise after sexual intercourse (honeymoon cystitis). The offending organisms include gram negative bacteria, such as E.coli, in 80-85% cases in women; it is also common in men. Most other cases in women are due to staphylococcus saprophyticus, though this is uncommon in case of males. This is a coagulase negative staphylococcus, which is normally considered benign but is actually a true urinary pathogen and should not be ignored. Rarely, klebsiella, proteus, enterococci, etc. may be isolated. Symptoms include low grade fever, dysuria, urgency, increased frequency of urination, and suprapubic abdominal pain. Occasionally women may have gross hematuria. There is suprapubic tenderness on examination without costovertebral angle tenderness. Urinalysis shows pyuria, bacteriuria, and hematuria. Hematuria is absent in female patients with urethritis and vaginitis, which can cause similar symptoms and can be used to differentiate the conditions. Urine culture is usually positive for the causative organism. Treatment is based on culture reports. Uncomplicated cystitis in women can be treated with a 3-day course of trimethoprim-sulfamethoxazole, trimethoprim alone, fluoroquinolone, or cephalexin. A 7-day course of nitrofurantoin is also adequate. Men should be evaluated for underlying conditions since uncomplicated cystitis is uncommon in males. A 7-day course is recommended even for uncomplicated cases in men.

Acute gastroenteritis, or food poisoning, has a similar picture but without costovertebral angle tenderness. Diffuse abdominal pain and watery diarrhea are the predominant symptoms. Fever may be low grade or high grade. UA is usually normal.

Acute salpingitis, or pelvic inflammatory disease, is characterized by lower abdominal pain and tenderness, abnormal vaginal discharge and/or bleeding, dyspareunia with adnexal tenderness, and cervical motion tenderness on a pelvic examination. An acute episode may present with high fever and chills, profuse vaginal discharge, and severe lower abdominal pain. Leukocytosis is found in less than 50% patients; UA is mostly normal and culture of the vaginal fluid should be done. Treatment is with broad spectrum antibiotics.

Acute diverticulitis is usually left sided and manifested by left lower quadrant abdominal pain and tenderness with diarrhea and occasionally low grade fever without chills. Leukocytosis may sometimes be present with sterile pyuria. The patient does not have back pain or costovertebral angle tenderness and seems well hydrated. Treatment is with ciprofloxacin and metronidazole for 7 - 10 days.
Correct answer:
Fasting serum glucose level

Explanation
The most likely cause of chronic kidney disease in the United States is diabetes, so a history of elevated blood sugars is important to know. This patient is noted to be somewhat overweight, putting her at higher risk for diabetes. A fasting serum glucose level would be useful to rule of diabetes mellitus.

Complete blood count may reveal anemia related to chronic kidney disease, but would not be useful in identifying the cause of kidney dysfunction.

Chronic urinary infections can lead to scarring of the renal interstitium and to chronic kidney disease. It is important to ask about this risk, particularly if other risk factors for kidney disease are not noted. A urine culture can be used to rule out urinary tract infection. However, in this patient with no signs or symptoms of urinary tract infection, urine culture is not likely to be a useful diagnostic test.

Hematuria can be caused by a variety of disorders including glomerular disease, acute and chronic infections, nephrolithiasis, renovascular disease, cystic kidneys, and urogenital cancers. It is prudent to ask about hematuria. Still, these disorders are less common than diabetic and hypertensive nephropathies, so they are not the most likely cause of her elevated creatinine.

Renal ultrasound can identify renal scarring, tumors, kidney stones, and other structural abnormalities that could be causing kidney dysfunction, but ultrasound is not a usual first-line screening test.
Correct answer:
Testicular torsion

Explanation
Testicular torsion in the adolescent boy is a urologic emergency, is the most common cause of acute scrotal swelling and pain, and is the most common cause of testicular loss. Torsion occurs 1 in 4000 and occurs most commonly on the left side in the United States. The cause is a congenital anomaly that occurs in approximately 12% of boys/men, in which the tunica vaginalis is attached too high, allowing the testicle to rotate freely on the spermatic cord and vascular pedicle in the tunica vaginalis. Approximately 40% of boys/men have the anomaly bilaterally. Testicular torsion usually occurs in ages 12-18 with the peak at 14. It may occur up to age 30, and it is found in infants and occasionally neonates at the time of birth. Up to 50% of patients may have had prior episodes of mild intermittent testicular pain that has resolved spontaneously due to intermittent torsion and spontaneous derotation

Associated symptoms may include nausea and vomiting (20%), fever (16%), abdominal pain (20-30%), and urinary frequency (4%). Physical examination may demonstrate a horizontal position of the testis, and it may be elevated compared to the uninvolved side. The cremasteric reflex is usually absent, but its presence does not rule out testicular torsion. Elevation of the scrotum does not relieve the pain. The diagnosis is clinical. Because it consumes precious time, ultrasound examination of the testis with color flow Doppler should only be ordered when the diagnosis is uncertain, and it can determine if there is blood flow to the testis. The studies are 86% sensitive and 100% specific in making the diagnosis if the only criterion is decreased blood flow. Radionuclide scans are 90-100% accurate in identifying decreased blood flow. Rapid diagnosis is critical; if surgical intervention is provided within 6 hours of onset, the salvage rate for the testis is 80-100%; after 6 hours, the salvage rate is approximately 0%.

Acute idiopathic scrotal edema is uncommon but presents acutely at age 6, on average. 90% of patients have a unilateral presentation. The scrotal skin is red and tender, but the testis appears to be normal. The redness tends to extend off the scrotum onto the perineum or onto the penis. This tends to resolve spontaneously in 48-72 hours and leaves no sequelae. Doppler ultrasound, if done, demonstrates good blood flow to the testis with peritesticular edema and fluid in the scrotal wall. Laboratory examination is normal except for occasional eosinophilia.

Acute epididymitis and/or orchitis is not a common pediatric diagnosis. It was first described in 1956. The onset tends to be more gradual, generally over a few days, with fever and dysuria. Elevation of the scrotum may reduce discomfort. The cause may be viral (adenovirus, mumps, Epstein-Barr virus) or bacterial. Bacterial infection is often associated with structural changes in the urinary tract. Urinalysis and urine culture may be helpful in establishing the diagnosis. Typical treatment is with rest, analgesia, and antibiotics if there is concern about a bacterial etiology. If a bacterial cause is identified, urinary tract imaging should be performed. There have been rare reports of acute epididymitis progressing to testicular infarction.

Torsion of the appendix testis may present similarly to testicular torsion. Tenderness is usually localized to the upper portion of the testis; typically, a blue dot is seen on the scrotal skin resulting from the venous congestion in the appendix testis. This is a self-limited condition and does not require surgical intervention. There are 5 appendages to the testis, all of which serve no function. If one twists or infarcts, symptoms result. Pain is less intense than with testicular torsion, and the cremasteric reflex is usually present.

Varicocele occurs in 10-15% of males, 16% of adolescents, and 20-40% of men evaluated for infertility. First described in adolescents in 1885, the most common age of presentation is adolescence and early adulthood. They are caused by incompetent or absent valves of the spermatic veins, resulting in dilatation of the veins of the pampiniform plexus. Rarely are they caused by compression of the renal vein by a tumor, an aberrant renal artery, an obstructed renal vein. Doppler ultrasonography can demonstrate retrograde blood flow. They are most common on the left side, are usually asymptomatic, but may present with vague scrotal discomfort and swelling. Of those with symptoms, 2% have intratesticular varicocele and these are more common on the right side. The typical physical finding is the bag of worms within the scrotal sac. They may be missed on physical examination in the supine position, so the patient should be examined in a standing position. Patients should be referred to urologists for further evaluation and to discuss options for treatment; it sometimes requires surgery.
Correct answer:
Nephrogenic diabetes insipidus

Explanation
This patient's symptom of excessive production of urine (polyuria) is most likely caused by nephrogenic diabetes insipidus secondary to lithium use. Lithium impairs the distal water reabsorption in the collecting ducts, mediated by vasopressin (ADH), leading to the production of large quantities of dilute urine. Unfortunately, lithium use for as short a period as 1 year can lead to irreversible damage of the renal tubules (via down-regulation and production of receptors and channels responsible for water reabsorption).

Treatments for lithium-induced nephrogenic diabetes insipidus include A) amiloride, a distal-tubule acting diuretic which competes with lithium for access to ion channels and thus prevents the lithium-induced polyuria, and B) hydrochlorothiazide with a low-salt diet, in order to effectively decrease the quantity of urine produced. Depakote can be substituted for lithium, but as mentioned above, lithium may cause irreversible tubular damage.

In central diabetes insipidus, decreased levels of ADH are produced by the posterior pituitary. Nephrogenic, not central diabetes insipidus, is the expected complication of lithium use. ADH is usually released in response to increases in serum osmolality and/or decreases in arterial volume. Non-osmotic causes such as nausea in post-opertive setting can also elicit ADH release. Head injury, granulomas, and other central nervous system abnormalities can lead to impaired ADH production and release. Central and nephrogenic diabetes are distinguished by a water deprivation test as described in the following table:
Correct answer:
Terazosin

Explanation
The correct response is terazosin .

Given the history, physical exam, and negative PSA, there is enough information to make the diagnosis of symptomatic benign prostatic hyperplasia (BPH); no further diagnostic studies are necessary. Benign prostatic hyperplasia (BPH), also known as benign prostatic hypertrophy, is a histologic diagnosis characterized by proliferation of the cellular elements of the prostate. A classic history is usually sufficient to make the diagnosis. Clinical manifestations include urinary hesitancy, urinary frequency, urgency, nocturia (awakening at night to urinate), decreased or intermittent force of stream, and/or a sensation of incomplete bladder emptying.

Depending on the patient's preferences, the next step is to begin treatment; in most cases, medical therapy is initiated first. If the symptoms do not significantly interfere with the patient's life, he may choose to wait and refuse treatment once he is reassured that he does not have a life-threatening illness (as in this case). If he selects treatment, management begins with a selective α1-receptor blocker (e.g., doxazosin or terazosin). A medication specific for α 1A-receptor subtype, such as tamsulosin (Flomax), may be used in patients who cannot tolerate traditional α1-receptor blockers. If medical therapy fails, or if a patient has severe BPH with ongoing obstruction, retention of large volumes of urine, or recurrent urinary tract infections, surgical therapy should then be considered. The most commonly performed surgery is transurethral resection of the prostate.

Finasteride is a 5 α-reductase inhibitor. If the patient does not receive sufficient relief from maximum doses of a α1-receptor blocker, it may be added; however, it may take up to 6 months for a 5 α-reductase inhibitor to result in a noticeable difference in symptoms. Finasteride is not a first-line treatment; the full therapeutic benefit of a α1-receptor blocker will be apparent within 4 - 6 weeks.

Because of the family history, this patient has an increased risk of prostate cancer; however, transrectal ultrasound with prostate biopsy is not indicated. This diagnostic procedure should be reserved for suspicion of prostate cancer. Based on this patient's family history and because he is African-American (African-Americans have a 50% higher incidence of, and mortality from, prostate cancer in comparison with Caucasians), a healthy index of suspicion is astute. Given this patient's classic BPH presentation and his normal PSA, prostate cancer is of low probability at this time. Caution must be exercised when using PSA as a diagnostic tool to rule in or rule out prostate cancer; the USPSTF recommends against PSA-based screening for prostate cancer.

In addition, the negative prostate exam on rectal probing, while classically taught to be important, adds no additional information in most cases; currently, it is not recommended by the United States Preventive Services Task Force.

No evidence in the case points towards the need for urine culture and sensitivity.

Post-void residual is a diagnostic tool used to determine if a patient with BPH will benefit from scheduled bladder catheterizations. A post-void residual >200 mL is associated with an increased risk of urinary tract infections. Scheduled catheterizations are usually reserved for cases in which medical and surgical interventions do not correct the problem; they are also used when medical and surgical interventions are contraindicated.
Correct answer:
CT scan with and without contrast kidney protocol

Explanation
Hematuria is the most common presenting sign of urinary tract cancer. Silent or painless hematuria suggests tumor or renal parenchymal disease. Renal cell carcinoma can present with flank pain, hematuria, persistent back pain, and an abdominal mass; also, it can be found incidentally on CT scan. So the clinical picture points to cancer, with renal cell carcinoma as the most likely diagnosis. The study of choice to evaluate the kidneys for masses is a CT scan with and without contrast kidney protocol. Any mass that enhances with IV contrast should be considered RCC until proven otherwise.

Bladder cancer often presents with gross hematuria, but it is most typically painless. The left flank pain and back pain are more characteristic of RCC. Bladder cancer is the second most common urologic cancer, and the mean age at diagnosis is 65. It is more common in men than women (2.7:1), and 98% of primary bladder cancers are epithelial malignancies (majority urothelial cell carcinomas). A cystoscopy is the diagnostic study of choice for suspected bladder cancer.

An MRI can help differentiate between a cyst and a solid lesion, but it is not the best study for suspected RCC.

A KUB can often miss some smaller solid lesions in the kidney, as can an IVP, especially if the lesion is not located in the renal collecting system. These are both useful in imaging stones.

The correct workup for hematuria includes both upper and lower urinary tract studies. Ideally, a patient would get both a CT scan with and without contrast kidney protocol and a cystoscopy, but you are looking for different things with each of these studies; in this patient, a CT scan is more likely to confirm your diagnosis.
Correct answer:
CT scan of abdomen and pelvis without contrast

Explanation
This patient most likely suffers from urolithiasis. Such patients typically present with unilateral renal colic that often radiates to the ipsilateral groin or testis and hematuria. These patients generally cannot sit still secondary to the pain and discomfort. They can also exhibit guarding, nausea, and vomiting in some cases. A stone protocol (non-contrast) CT scan has become the standard initial workup of patients with suspected stone. This study is especially useful in the emergency department since it can quickly and effectively diagnose urolithiasis. A CT scan gives the most information (location and size of the stone, hydronephrosis, any anatomical variations, etc.) to the urologist who will likely see the patient. Stones are more common in men than women (3:1), and initial presentation is typically in the third or fourth decade of life.

MRIs are used more often in assessing soft tissues; they are not typically useful in urolithiasis cases.

Ultrasound of the kidneys can reveal hydronephrosis and cystic or solid lesions. Stones can sometimes be assessed as well, but small stones are occasionally not visible.

A kidney, ureter, bladder X-ray will show approximately 90% of stones. Uric acid stones are not visible on plain film, and some stones are difficult to see because of size or location. A KUB is a viable option but not the best study to order.

Intravenous urogram is most useful after a thorough bowel preparation, so a non-emergent study will typically yield more information than an emergent study. However, if a high-grade obstruction is suspected, emergent intervention with intravenous urogram may be warranted. These patients can have an elevated temperature and a CT scan can show high-grade obstruction, so that is still the best initial study.
Correct answer:
Ciprofloxacin 500 mg PO BID x 14 days

Explanation
Ciprofloxacin 500 mg PO BID x 14 days is the correct answer. Patients with pyelonephritis who are sick enough to be treated as an inpatient receive IV antibiotics until they have been afebrile for 24-48 hours. They also must be able to tolerate oral hydration and oral medications before being discharged. Upon discharge, they will be given a prescription for antibiotics that will complete at least 2 weeks of antibiotic treatment. Ciprofloxacin has good coverage for E. coli urinary tract infections, and given at 500 mg PO BID x 14 days would be an appropriate choice as long as sensitivities from her culture showed ciprofloxacin to have sensitivity.

Motrin 800 mg PO q 8 hours prn pain is not the correct answer. While Motrin is a good choice for patients who may still have some discomfort related to the pyelonephritis, it is not the most likely prescription for this patient to receive. She had become asymptomatic prior to discharge, so there would not be any reason to prescribe anything to help with pain or discomfort at that time. In addition, she is more likely to receive treatment for her infection than for pain.

Nitrofurantoin 100 mg PO BID x 7 days is not the correct answer for several reasons. While nitrofurantoin is often an appropriate antibiotic for E. coli urinary tract infections, it does not achieve tissue levels reliable enough for pyelonephritis treatment. In addition, only 7 days of treatment does not add up to at least 2 weeks total of antibiotics.

Fluconazole 150mg PO daily x 7days is not the correct choice. This is an antifungal medication is would not have an indication to use as treatment is this patient case.

Amoxicillin 500 mg PO BID x 14 days is not the correct answer. While 14 days of antibiotics is a good length of time, amoxicillin does not have good coverage for E. coli, so it would not be a good choice to treat an E. coli-related pyelonephritis.
Correct answer:
Non-contrast CT abdomen or renal ultrasound to evaluate for analgesic nephropathy

Explanation
A CT of the abdomen should detect reduced renal size and lumpy bumpy contour present in analgesic nephropathy. This patient has consumed non-steroidals frequently and long enough to put him at risk for analgesic nephropathy. In the absence of any other overt cause for kidney disease, this diagnosis should be explored.

Chronic analgesic consumption is associated with chronic kidney disease. Analgesic nephropathy is still a relatively uncommon cause of chronic kidney disease; its prevalence is higher in Europe and Australia than in the United States, where it accounts for only 2-4% of the cases of end-stage kidney disease.

Some studies have debated causality; however, a New England Journal of Medicine article addressed the risk in patients with chronic consumption and found a 2.5-5 fold increase risk of chronic renal failure in patients who chronically used acetaminophen versus those who did not. Cumulative lifetime use increased the odds of renal failure and results were similar for patients who took aspirin. The highest risk was noted among patients who took >500g/yr acetaminophen (>1.4g/day). Other studies have found increased risk among users of >3-5 gram per lifetime and >6 tablets/day for 3 years.

This patient is not at a particularly elevated risk for renovascular disease, given his lack of other vascular disease and lack of smoking. Renovascular disease is an important cause of chronic kidney disease, particularly in elderly populations, and its evaluation might be considered if asymmetric renal size is detected or no other cause for the elevated creatinine is found. Angiograms do pose an iatrogenic risk, and it is debatable if anything could be done to treat renovascular disease if it should be detected. The kidney damage will depend on the duration and degree of vascular impairment. Furthermore, antihypertensives are often quite effective in the management of renovascular hypertension.

This patient has no known risk factors for hepatitis and should not be at risk for hepatitis associated causes of kidney disease (glomerular diseases including membranous and membranoproliferative glomerulonephritis and cryoglobinemia).

A post-void bladder scan could detect urinary retention. This is a relatively easy diagnostic test. This patient apparently has no symptoms of urinary retention and has a normal physical exam, so urinary retention is a less likely cause.

Although the urinalysis showed a few red and white cells, it was leukocyte esterase and nitrite negative. In an asymptomatic patient, an occult urinary tract infection is less likely. Additionally, there are no symptoms of urinary retention to put him at risk for getting a urinary infection. Imaging the kidneys is a better choice. Chronic infections can be a cause of kidney disease by leading to scarring of the renal interstitium.
Correct answer:
Urge incontinence

Explanation
This patient most likely has urge incontinence.

In urge incontinence, patients typically have involuntary leaks, increased urinary frequency, and nocturnal incontinence either during or just after the sensation of needing to void. Symptoms are not exacerbated by increased abdominal pressure or the stress of coughing/sneezing. Bladder detrusor muscles may be overactive, leading to the unexpected release of urine. Treatments include scheduled voiding and anticholinergic medications (oxybutynin, etc.).

Stress incontinence is characterized by the involuntary leaking of urine during stress or increases in abdominal and bladder pressure, such as coughing and sneezing. Bladder pressure at these times exceeds urethral pressure, allowing urine to leak through the urethra. Urinary tract deficits are found commonly in older patients; both men and women have decreased bladder sensation, decreased contractility, and involuntary bladder contractions, which predispose them to incontinence.

Obesity, pregnancy, and vaginal births may increase the risk for stress incontinence. In such cases, the pelvic floor muscles may be insufficiently strong to support the urethra and overcome pressure of urine flowing from the bladder.

Mixed incontinence refers to the presence of symptoms of both stress and urge incontinence. It may be seen in 1/3 of patients.

Overflow incontinence refers to urinary leaks that occur due to an obstruction of urine flow. In the absence of urinary retention, post void residuals are typically elevated; normal post-void residuals in the absence of retention are less than 200 ml. His 30 ml post-void urine volume is not consistent with urinary retention. Initially, patients with urinary retention may experience dribbling after voids, straining, the sensation of a full bladder, and a constant urge to void. Prostatic hypertrophy, atonic bladders, etc. can impede urine flow. Once urine volume exceeds bladder capacity, it may spill out, causing a leak. Overflow incontinence may be distinguished from urge incontinence by urodynamic testing, and it may be treated with terazosin and finasteride.

Many medical problems and medications can contribute to incontinence. Delirium, restricted mobility, urinary infection, fecal impaction, polyuria, and medications that decrease urethral pressure (e.g., alpha blockers, neuroleptics, and benzodiazepines) or increased bladder pressure (e.g. anticholinergics, beta blockers, anti-Parkinson's medications, and bethanechol) may contribute to incontinence.

The normal rectal examination and the history of regular bowel movements make fecal impaction a less likely diagnosis in this case.



References
Correct answer:
Discontinue ibuprofen.

Explanation
This patient has a history and findings consistent with acute (tubulo) interstitial nephritis (AIN) and should discontinue ibuprofen. AIN is an immune-mediated form of acute kidney injury (acute renal failure).

Patients develop varying degrees of renal failure, which are characterized by changes in urine output, electrolyte imbalances, acidemia, and azotemia (elevations in serum creatinine with or without nausea, sleep disturbances, shakiness, etc.) in response to viral, bacterial, immunological, or pharmaceutical insults.

A variety of antibiotics, ACE inhibitors, proton pump inhibitors, seizure medications, etc. are known to cause AIN. The development of AIN is not dependent on the dose of the medication given. Many infections, including HIV, EBV, and mumps, along with immunological diseases such as lupus and Wegener's granulomatosis can also cause AIN.

In the case of this patient, no other triggers for AIN were noted, and ibuprofen is the likely cause.

AIN is treated by removing the offending medication and avoiding its future use. If AIN occurs in the setting of an infection or immunologic or neoplastic process, that disease should be treated.

Discontinuing the offending medication (if still in use) may cause resolution of illness in a couple of weeks. Patients with incomplete resolution may improve slowly over months. Symptoms, urine output, volume status, serum creatinine, and electrolytes should be monitored to evaluate the need for dialysis.

Although he has an elevated serum creatinine, this patient lacks the traditional indications for dialysis, such as uncontrollable hyperkalemia, acidemia, volume overload, and uremia (azotemia + pericardial rub, encephalopathy, and/or asterixis).

If renal failure does not improve within a few days of discontinuing the offending medication, patients with AIN can be started on prednisone therapy for a couple of weeks, to be tapered thereafter.

For patients with AIN unresponsive to steroid therapy, immunomodulatory therapy such as cyclophosphamide (Cytoxan) can be considered to target the tubular and interstitial irritation that is occurring. Immunomodulatory therapy is premature in this case because other therapeutic maneuvers have not been attempted. Routine steroid therapy is not advised in the treatment of AIN.

Cyclophosphamide therapy has many side effects, including neutropenia, and patients on this therapy require close monitoring for infections and decreasing blood counts.



References
Waikar SS, Bonventre JV. Acute Kidney Injury. In: Kasper D, Fauci A
Correct answer:
Plan voiding ureterocystogram

Explanation
Urinary tract infections (UTIs) are common in children and may cause permanent kidney damage. Urinary tract anomalies are risk factors for UTIs, and you should search for them in a boy of this age. While voiding cystourethrography (VCUG) is not recommended routinely after the first UTI, it should be performed if there is a recurrence, particularly a recurrence of febrile UTIs. Kidneys and bladder ultrasound are performed in younger children (3 - 5 years of age) as the initial step to evaluate anatomy, but they cannot relieve vesicoureteral reflux (VUR).

Recommendations regarding antimicrobial prophylaxis still lack evidence, both for and against regardless, in this case, your approach should be based on the diagnosis of the presence of eventual urinary tract anomalies.

You should tell the patient's mother that circumcision reduces UTIs, especially in high-risk boys; however, it is more important to exclude the presence of anatomical abnormalities, which put this boy at an even bigger risk.

Voiding dysfunction is defined as daytime voiding disorders in children who do not have neurologic, anatomic, obstructive, or infectious abnormalities of the urinary tract. It is recommended that toilet training begin when a child is 18 months old and shows the interest. A child's interest usually appears around 24 - 25 months. Daytime dryness is usually achieved by 3 years of age. Dysfunctional voiding can lead to VUR, accidental urinary leakage, and UTIs; however, it is too early to think about the presence of dysfunctional voiding in this child.

Both radionuclide cystography and voiding cystourethrography are used in detecting and grading vesicoureteral reflux. While VCUG is suggested for both girls and boys, radionuclide cystography is suggested only for girls because voiding cystourethrography is needed for adequate anatomic imaging of the urethra and bladder in boys.



References
Correct answer:
Nephrogenic diabetes insipidus

Explanation
A known side effect of lithium is nephrogenic diabetes insipidus. This side effect is very common. Nephrogenic diabetes insipidus results when the collecting duct of the kidney does not respond to the antidiuretic hormone (ADH).

Antidiuretic hormone (ADH) is also known as arginine vasopressin. It is secreted from the pituitary. It works on the collecting tubules of the kidney to conserve water.

Nephrogenic diabetes insipidus is characterized by renal resistance to ADH. This results in a large output of dilute urine. There will be polyuria and polydipsia. Hypernatremia would be present. In contrast to central diabetes insipidus, plasma ADH level would be elevated and there is no response to the administration of vasopressin. Nocturia can be present.

In complete nephrogenic diabetes insipidus, the kidney is unresponsive to ADH. Therefore, exogenous vasopressin (ADH) will not increase the urine osmolality.

The syndrome of inappropriate ADH secretion (SIADH) is due to excess ADH (antidiuretic hormone) or an ADH like substance. The syndrome of inappropriate ADH secretion is characterized by concentrated urine. There will be an accompanying serum hyponatremia. Hyponatremia can cause central nervous system symptoms (obtundation, seizure, and coma).

Central diabetes insipidus is characterized by a lack of antidiuretic hormone (ADH) secretion from the pituitary. Because of the deficiency of ADH, there is an inability of the kidney to concentrate the urine. This results in a large urine output of dilute urine. There will be polydipsia and polyuria. Nocturia can be present. Hypernatremia would be present. In contrast to nephrogenic diabetes insipidus, there is an increase in urine osmolality in response to the administration of vasopressin.

Diabetes mellitus is due to an absolute or relative insulin deficiency. Untreated, it is characterized by polyuria, polydipsia, and polyphagia, and there will be an elevated blood glucose and glucosuria. Glucosuria is the presence of glucose in the urine.

Psychogenic polydipsia is a psychological condition. A patient with psychogenic polydipsia drinks an enormous amount of water. Because of this large water intake, there is polyuria. However, with psychogenic polydipsia nocturia is usually absent. There will also be hyponatremia.
Correct answer:
IgA nephropathy

Explanation
Both gross and microscopic hematuria a couple of days after nonspecific upper respiratory tract infection and hypertension in male patients are highly suggestive on IgA nephropathy (Bergers disease). IgA nephropathy is the most common chronic glomerular disease worldwide. It may also be associated with gastroenteritis, acute or chronic renal failure, or may be asymptomatic when erythrocytes (RBCs), RBC casts, and proteinuria are discovered on urinalysis. Some patients also have hypertension. Pathophysiological mechanisms are subendothelial deposits of amorphous material that lead to vascular occlusions, mechanical RBC, and platelet damage, resulting in prothrombotic state.

Alport syndrome is hereditary X-linked dominant hereditary nephritis that will also present with hematuria (asymptomatic or gross) 1-2 days after upper respiratory infection. This progressive hereditary nephritis will, however, be accompanied with bilateral sensorineural deafness and visual problems (patognomonical extrusion of central part of lenses into anterior ocular chamber).

Amoxicillin side effects are not probable. Amoxicillin side effects include nausea, vomiting, rashes, antibiotic-associated colitis, and diarrhea, in addition to more rare side effects such as mental changes, lightheadedness, insomnia, confusion, anxiety, sensitivity to lights and sounds, and unclear thinking. Even allergy to amoxicillin presents with a change in mental state initially, followed by itching skin rash, fever, nausea, and vomiting any time during the treatment up to a week after treatment has stopped. Acute overdose of amoxicillin may manifest with renal dysfunction, lethargy, and vomiting, but this usually happens in very young children.

Acute poststreptococcal glomerulonephritis can present with the same clinical picture: sudden hematuria, edema, and hypertension, usually together with non-specific constitutional symptoms. However, there is always a latent period between the streptococcal infection and the onset of signs and symptoms of acute glomerulonephritis. Latent period is 1-2 weeks after a throat infection and 3-6 weeks after a skin infection.

Hemolytic-uremic syndrome (HUS) is acute renal failure associated with non-immune (Coombs-negative) microangiopathic hemolytic anemia and thrombocytopenia. It is the most common cause of acute renal failure in children (though it may occur in adults as well). In HUS, there is usually a prodromal gastroenteritis, fever, or bloody diarrhea for 2-7 days before the onset of renal failure, sometimes with central nervous system signs (irritability, lethargy, even seizures). Acute renal failure with anuria follows. Physical findings may reveal hypertension, edema, fluid overload, and severe pallor.
Correct answer:
Referral to surgeon for surgery within 14 days

Explanation
A scrotal mass that does not transilluminate and worsens with crying, coughing, or Valsalva maneuver in an infant is highly suggestive of inguinal hernia. "Silk sign," as described in the question, is felt when the hernia sac is palpated over cord structures, and it further supports the diagnosis. Because there is a high rate of incarceration in infants with inguinal hernia (14 to 31%), surgical repair is the recommended treatment. One study found that waiting beyond 14 days after diagnosis of inguinal hernia increased the rate of incarceration by 7%. It is not an emergency surgery unless complications are present, but it should be done as soon as possible after the diagnosis.

Watchful waiting until 1 year of age would be an appropriate treatment for infants with hydrocele because there are rarely complications; the hydroceles usually resolve on their own before 1 year of age.

Scrotal slings are not typically used in infants. They are sometimes used in adults with inguinal hernias.

Inguinal hernias in infants need surgical repair. The risk of incarceration is too high to send parents home with reassurance only. Reassurance with follow-up would be appropriate treatment for hydrocele.

Patient education on incarceration (hernia that is not easily reduced) and strangulation (incarcerated hernia with signs of vascular compromise) is extremely important in all cases of hernias; however, this is not a sufficient treatment plan and follow-up should be sooner than 2 months.
Correct answer:
Doxazosin

Explanation
This patient most likely has obstructive uropathy secondary to an enlarged prostate and will benefit from doxazosin, which will both relieve symptoms of urinary retention and prevent the renal damage it may cause. His enlarged prostate and elevated post-void residual (>200 mL) are consistent with the diagnosis.

Obstructive uropathy can occur from compression of any portion of the urinary tract; prostatic enlargement or bladder stones may impede flow through the urethra, and oncologic and gastrointestinal processes may obstruct ureters. Neurologic diseases and medications may impair bladder emptying and lead to urinary retention. Prolonged acute obstruction and/or chronic obstruction may cause declining glomerular filtration rates, inability to concentrate urine, inability to properly acidify the urine, and dysfunctional sodium and potassium excretion.

The patient currently has no disorders of bicarbonate or potassium, so he will likely not benefit from their administration. As above, he should be monitored for them because they do occur with chronic obstruction. Likewise, he currently has no evidence of infection (e.g., fever, leukocytosis, pyuria).

He is predisposed to urinary infections given his impaired flow; if he does develop chronic urinary infections, they may contribute to intrinsic renal disease and scarring.

The patient should continue normal intake of fluids, but with increased intake, his kidneys are at risk for failure if he cannot control his outlet flow obstruction.
Correct answer:
Short Q-T interval

Explanation
Your patient has nonspecific symptoms, but the history of spinal cord injury, immobilization, kidney stones, and renal insufficiency suggests the presence of hypercalcemia. Prolonged immobilization may result in hypercalcemia, hypercalciuria, and osteoporosis because of the suppression of parathyroid-1,25-dihydroxyvitamin D axis. Hypercalciuria develops within the first week after injury and continues for 6 - 18 months. Hypercalcemia will occur when the rate of calcium resorption exceeds the capacity of urinary excretion. It usually happens 4 - 8 weeks after spinal cord injury. Children, adolescents, and persons with impaired renal function are particularly prone to hypercalciemia. Elevated calcium in an immobilized patient increases osteoclastic bone resorption because of the lack of signals from active muscles through the osteocytes. The release of calcium suppresses production of parathyroid hormone, resulting in increased serum phosphate and reduced synthesis of 1,25-dihydroxyvitamin D.

The most common ECG abnormality associated with hypercalcemia is a shortened Q-T interval.

A patient with ventricular fibrillation will not be able to give you his or her history.

QT prolongation is seen in hypocalcaemia because of the prolongation of ST segment.

Fusion of QRS-T is an ECG characteristic of hyperkalemia. Hyperkalemia also may demonstrate wide low P-waves, wide QRS, loss of the ST segment, and tall tented T waves.

Torsades de pointes are usually caused by hypokalaemia, hypomagnesaemia, or, sometimes, with hypocalcaemia.
Correct answer:
Testicular malignancy

Explanation
This patient's physical exam findings suggest testicular malignancy. In the United States, the incidence of testicular cancer in African Americans is approximately 1/4 of that in Caucasians. Within a given race, individuals in the higher socioeconomic classes have approximately twice the incidence of those in the lower classes. Testicular cancer is slightly more common on the right side than on the left, coinciding with higher rates of right cryptorchidism. Of all acquired and congenital risk factors, cryptorchidism is the strongest associated risk factor associated with testicular cancer. Placement of the cryptorchid testis into the scrotum (orchiopexy) does not alter the malignant potential of the cryptorchid testis, but it does facilitate examination and tumor detection.

The most common symptom of testicular cancer is a painless enlargement of the testis. Enlargement is usually gradual, and a sensation of testicular heaviness is not unusual. Acute testicular pain is seen in approximately 10% of cases and may be the result of intratesticular hemorrhage or infarction.

Approximately 10% of patients are asymptomatic at presentation, and the tumor may be detected incidentally following trauma or by the patient's sexual partner. On physical exam, a testicular mass or diffuse enlargement is found in most cases. The mass is typically firm and nontender, and the epididymis should be easily separable from it. A hydrocele may accompany the testicular tumor and help to camouflage it. Transillumination of the scrotum can help to distinguish between these entities.

Palpation of the abdomen may reveal bulky retroperitoneal disease; assessment of supraclavicular, scalene, and inguinal nodes should be performed. Gynecomastia is present in 5% of all germ cell tumors but may be present in 30-50% of Sertoli and Leydig cell tumors. Its cause seems to be related to multiple complex hormonal interactions involving testosterone, estrone, estradiol, prolactin, and hCG. Hemoptysis may be seen in advanced pulmonary disease.

Findings consistent with epididymitis are an enlarged tender epididymis associated with fever, urethral discharge, and irritative voiding symptoms.

A translucent, fluid-filled hydrocele should be visualized by transillumination of the scrotum.

Orchitis presents with inflamed, painful, tender, and swollen testes.

A varicocele, which is an engorgement of the pampiniform plexus of veins in the spermatic cord, should disappear when the patient is in the supine position. It is frequently described as a "bag of worms" that is separate from the testes.
Correct answer:
Addition of diuretic to lisinopril and follow potassium

Explanation
The correct response is addition of diuretic to lisinopril and follow potassium.

This patient has not recently taken ibuprofen, making it an unlikely cause of her hyperkalemia. Ibuprofen and other non-steroidals can cause hyperkalemia by decreasing glomerular filtration rate, decreasing distal delivery of sodium (Na), thereby decreasing Na for potassium (K) exchange and flow for K excretion via flow-activated K channels.

Sodium polystyrene sulfonate sorbitol is an exchange resin combined with a laxative. It exchanges potassium and sodium; it can be removed from the body in 4 - 24 hours if it produces a bowel movement. Many patients find it unpleasant tasting and do not like the laxative effect. It is possible that some patients would not want to take it daily.

It is uncertain if bicarbonate administration would lower the potassium level.

Lisinopril can elevate potassium by disrupting the renin-aldosterone-angiotensin system and inhibiting aldosterone-mediated potassium secretion.

Presumably, this patient had a compelling indication (i.e., diabetes, albuminuria) to use lisinopril as a first-line blood pressure medication; African Americans without diabetes and or proteinuria might use diuretics or calcium channel blockers as first line antihypertensives. Goal blood pressures for patients >60 are generally less than 150/90 mm hg; the presence of proteinuria tightens this goal to less than 140/90 mm hg. The addition of a diuretic should increase distal delivery of sodium and assist with potassium excretion.
Correct answer:
Renal cell carcinoma

Explanation
Hematuria is the most common presenting sign of urinary tract cancer. Silent or painless hematuria suggests tumor or renal parenchymal disease. Renal cell carcinoma can present with flank pain, hematuria, persistent back pain, and an abdominal mass. It can also be found incidentally on CT scan, so the clinical picture points to cancer with renal cell carcinoma as the most likely diagnosis. Smoking is a risk factor for renal cell cancer. RCC is more common in men than women (2:1), and it has a peak incidence in individuals in their 50s.

Bladder cancer often presents with gross hematuria, but it is most typically painless. Bladder cancer can present with pain if the cancer is blocking the ureter. The left flank pain and back pain are more characteristic of RCC. Bladder cancer is the second most common urologic cancer, and the mean age at diagnosis is 65. It is more common in men than women (2.7:1) and 98% of primary bladder cancers are epithelial malignancies (majority urothelial cell carcinomas).

Acute cystitis typically presents with irritative voiding symptoms (frequency, urgency, dysuria) and suprapubic discomfort in addition to possible hematuria. Urinalysis will show pyuria, bacteriuria, and varying degrees of hematuria. Urine cultures will show specific organisms.

Urethritis is inflammation of the urethra that presents with urethral discharge, dysuria, and itching. Urethritis is most often caused by an STD. This patient does not have a history of unprotected sexual intercourse or any other symptoms that would indicate this diagnosis.

Ureteral calculi can present with hematuria; it also typically presents with flank or abdominal pain, but not abdominal mass. If the stone is in the ureter, it often causes some hydroureter with or without hydronephrosis, both of which cause some pain or discomfort. The patient has no past history of forming stones.
Correct answer:
Tubulitis, interstitial infiltrate

Explanation
This patient has findings suggestive of acute interstitial nephritis (AIN) and most likely will have tubulitis and interstitial infiltrates noted if she undergoes a renal biopsy.

AIN is an immune-mediated form of acute kidney injury (acute renal failure).

Patients develop varying degrees of renal failure, characterized by changes in urine output, electrolyte imbalances, acidemia, and azotemia (elevations in serum creatinine with or without nausea, sleep disturbances, shakiness, etc.) in response to viral, bacterial, immunological, or pharmaceutical insults.

A variety of antibiotics, ACE inhibitors, proton pump inhibitors, seizure medications, etc. are known to cause AIN. The development of AIN is not dependent on the size of the dose of the medication given. Many infections, including HIV, EBV, and mumps, can also cause AIN. Additionally, immunological diseases, such as lupus and Wegener's granulomatosis, can cause AIN.

Diagnosis is made by history of exposure, findings if noted of rash/fever/arthralgias, and the presence of pyuria, white cell urinary casts, and elevated erythrocyte sedimentation rate. Urinary eosinophils may be noted, but may also occur in the setting of other bladder or renal abnormalities, so they are not specific.

Treatment involves removal of offending drugs, treatment of infections, monitoring urine volume, and laboratories for the need for dialysis support. Steroids have been used if patients do not respond to the above within a few days, but they may not hasten recovery (Clarkson). Immunomodulatory therapy (e.g., cyclophosphamide) has also been used.

Red cell tubular casts are suggestive of glomerulonephritis. Glomerulonephritis occurs secondary to infectious, immunological, and neoplastic processes.

Kimmelstiel-Wilson nodules are characteristic of diabetic nephropathy.

Diabetic nephropathy is a complex disease found in many type I and II diabetics. It is the leading cause of end stage kidney disease in the United States.

Necrosis of proximal tubules is characteristic of acute tubular necrosis (ATN).

ATN is a form of acute tubular injury more common in the inpatient setting.

Medications, infections, and renal hypoperfusion secondary to sepsis +- cardiac failure may lead to injury of the renal tubules.
Correct answer:
Bed-wetting alarm system

Explanation
Bedwetting, or enuresis, is a common problem in the pediatric age group. Prevalence at the age of 5 years is 7% in boys and 3% in girls. At the age of 10 years the prevalence is 3% for males and 2% in females. Enuresis is divided into primary enuresis, where the child has never been dry at night, and secondary enuresis, where the child who has been continent for at least 6 months starts to wet the bed again. Primary nocturnal enuresis is associated with a smaller bladder capacity, abnormal arousal patterns during sleep, and inappropriate or inadequate toilet training. Secondary enuresis is generally precipitated by situations of psychological stress, such as a recent move, marital conflict, or a new sibling in the household. Only rarely does enuresis have an organic component; usually urological procedures are not warranted.

General treatment guidelines that patients and especially the parents should be educated on include voiding before retiring, limiting fluids prior to bedtime, and expecting older children to clean their own bedding.

More often than not, the first line intervention is considered bed-wetting alarms. These have been found in multiple studies to be extremely effective in producing a long-term cure. The bed-wetting alarms are moisture-sensing devices that are placed near the child's genitals, and are activated to trigger an alarm when the child voids in bed. These alarms go off at the initial first few drops of voiding, thereby awakening the child to get out of bed and finish voiding in the toilet or hold urine until later. This evokes a conditioned response of waking and inhibiting urination. They are generally recommended in children older than seven years. Therapy is recommend for at least three months and used every night. Parents must get up with the child to ensure the child does not just turn off the alarm and go back to sleep. If used appropriately, bed-wetting alarms are successful in 2/3 of the patients that utilize them.

Alarm therapy requires a cooperative, motivated child and family. Parental involvement plays an essential role when using alarm devices due to the consistency that is necessary. Treatment must involve education and avoidance of being judgmental and even shaming the child due to most children feeling ashamed; the goal of treatment is to help the child establish their continence and at the same time maintain or gain self-esteem.

It is recommended that children use these alarm devices until they experience three weeks of complete dryness. For complete resolution of nocturnal enuresis, the bed-wetting alarm may be needed to be used for up to 15 weeks. Relapse rates are higher when the alarm system is discontinued after shorter dry periods. Studies have shown that compared with other skill-based or pharmacologic treatments, the bed-wetting alarm has a higher success rate (75%) and a lower relapse rate.

Desmopressin and imipramine are the primary drugs used in the treatment of nocturnal enuresis but should not be considered first line interventions. Imipramine administration is only slightly less effective than the alarm systems in bringing about dryness, usually within 2 weeks. Long-term results are less promising, as the enuresis tends to return while off the medication.

Desmopressin acetate typically has an excellent response over the short-term, but again, the enuresis tends to recur when the child is taken off the medication.

Fluid restriction and wearing diapers at night may resolve the consequences of the issue but will not create the behavior which will lead to the actual bedwetting from stopping; behavioral modification/training is a main key to treatment.
Correct answer:
Bladder cancer

Explanation
Any time a patient's chief complaint resembles frank hematuria, bladder cancer must be assumed until proven otherwise. In fact hematuria in general, whether it is gross or microscopic, chronic or intermittent, is the presenting symptom in up to 85-90% of patients diagnosed with bladder cancer. It occurs more commonly in men than women and the mean age at diagnosis is around 73 years of age. Cigarette smoking and exposure to industrial dyes or solvents are known risk factors for this type of carcinoma. The patient above fits many of these components. Patients may also potentially have irritated voiding symptoms, although not always. A patient with a urinary tract infection (UTI) is extremely rare in men. Because this patient is not having any other symptoms other than the painless hematuria, one may still keep the diagnosis of a UTI on the differential diagnosis list.

Symptomatic nephrolithiasis typically will cause the patient excruciating pain, usually in the flank areas. Nausea and vomiting may also be present. The location of this pain may correspond with the movement of the stone through the urinary tract. This is also inconsistent with the presenting patient in the above scenario.

The pathology of diabetes mellitus itself does not cause hematuria, but rather the increase incidence of urinary tract infections in diabetics is what may increase this potential.

Either acute or chronic prostatitis is not as likely due the fact that this gentlemen is not experiencing any irritating voiding symptoms fever, or even perineal or suprapubic pain.
Correct answer:
Recommend scheduled voiding.

Explanation
This patient likely has a neurogenic bladder as a complication of her diabetes and should be initially advised to attempt scheduled voids. By voiding on a schedule, she'll empty her bladder and prevent the excessive buildup of urine that may lead to incontinence.

If scheduled voids are unsuccessful, she may try intermittent self-catheterization using a sterile technique. Unfortunately, any catheterization has an infection risk. Foley catheters, suprapubic catheters, and nephrostomy tubes may all become infected. Furthermore, voiding may be achieved without them.

This patient did not fully empty her bladder with voiding, but she did not have a post-void residual consistent with urinary retention; post-void residuals >200 mL are suggestive of retention. Her problem may be both impaired sensation of voiding in addition to impaired muscle contractility; cystometry may elucidate this further.

Bethanechol and neostigmine are cholinergic agonists and may stimulate bladder emptying. They have a variety of side effects, including bradycardia. This patient's heart rate is 60 beats per minute and bethanechol may not be advised.

Diabetic cystopathy may be complicated by urinary tract infections, urinary leaks and retention, bladder stones, and chronic kidney disease (Sasaki). It may also exacerbate kidney dysfunction secondary to diabetic glomerulosclerosis. This patient has microalbuminuria (>30 mg urine spot microalbumin), a sign of diabetic nephropathy and a calculated glomerular filtration rate of 59 mL/min/1.73 m2. Every attempt should be made to preserve renal function, including initiating renin-angiotensin system blockade and preventing loss of renal function secondary to urinary tract obstruction.
Correct answer:
Normal saline

Explanation
This patient is presenting with signs and symptoms consistent with hypovolemic shock due to acute traumatic blood loss.

3 goals exist in the emergency department treatment of the patient with hypovolemic shock as follows: (1) maximize oxygen delivery - completed by ensuring adequacy of ventilation, increasing oxygen saturation of the blood, and restoring blood flow, (2) control further blood loss, and (3) fluid resuscitation.

Current recommendations are for aggressive fluid resuscitation with lactated Ringer solution or normal saline in all patients with signs and symptoms of shock, regardless of underlying cause.

If a patient is moribund and markedly hypotensive (class IV shock), both crystalloid and type O blood should be started initially. These guidelines for crystalloid and blood infusion are not rules; therapy should be based on the condition of the patient.

Epinephrine is indicated as initial resuscitation management in cardiac arrest, anaphylactic shock, symptomatic bradycardia, and hypotension refractory to volume replacement. Epinephrine is associated with a host of adverse effects such as induction of pulmonary hypertension, tachyarrhythmia, myocardial ischemia, lactic acidosis, hyperglycemia and compromise hepatosplanchnic perfusion, oxygen exchange, and lactate clearance.

The combination of hypertonic saline and dextran also has been studied because of previous evidence that it may improve cardiac contractility and circulation. Studies in the US and Japan have failed to show any difference when this combination was compared with isotonic sodium chloride solution or lactated Ringer solution.

Somatostatin and octreotide infusions have been shown to reduce gastrointestinal bleeding from varices and peptic ulcer disease. These agents possess the advantages of vasopressin without the significant side effects.

In the patient with GI bleeding, intravenous vasopressin and H2 blockers have been used. Vasopressin commonly is associated with adverse reactions, such as hypertension, arrhythmias, gangrene, and myocardial or splanchnic ischemia. Therefore, it should be considered secondary to more definitive measures. H2 blockers are relatively safe but have no proven benefit.
Case Ico-delete Highlights
A 12-year-old boy presents with a 3-hour history of extreme, severe pain in the right testis. It started suddenly, is 8/10 in intensity, and does not radiate. It is associated with nausea and scrotal swelling. He never had such pain in his lifetime, and he denies any problem in urination. He has never been operated on, and he denies any history of trauma. He is allergic to penicillin.

On physical exam, the child is in visible distress. Temperature is 37°C, heart rate is 95, blood pressure is 120/70 mm Hg, and respiratory rate is 20 per minute. Genital examination reveals enlargement and edema of the entire scrotum. The right testicle is erythematous and tender to palpation; it appears to sit higher and lies horizontally in the scrotal sac relative to the left side. The cremasteric reflex is absent ipsilaterally, and there is no relief of pain upon elevation of the scrotum (Prehn's sign). Abdomen is non-tender and tympanic to percussion in all 4 quadrants. Bowel sounds are audible. Chest auscultation shows normal vesicular breathing with mild crepitations over the lower lung fields. Cardiac exam reveals normal S1 and S2, without rubs, murmurs, or gallop.

His initial labs show a hemoglobin of 14.5 g/dL, WBC of 13,000/mm3, platelets of 210,000/mm3, sodium of 140 mmol/dL, potassium of 3.8 mmol/dL, chloride of 95 mmol/dL, urea of 25 mg/dL, and creatinine of 0.9 mg/dL.



Question
What clinical feature helps most to differentiate the patient's condition from other causes of scrotal pain?
Correct answer:
Urinalysis

Explanation
Enuresis means any involuntary loss of urine. If it is used to denote incontinence during sleep, it should always be qualified with the adjective "nocturnal." Nocturnal enuresis is defined as involuntary urination in sleep without urological or neurological causes after the age of 5 years, at which time bladder control would normally be expected. The classification of enuresis is based on whether the child has ever achieved bladder control. Primary enuresis refers to a child who has never been dry; whereas, secondary enuresis means the child has been dry for a period but becomes enuretic later.

Another useful classification is based on a period when the child does not have bladder control:

• Nocturnal enuresis: Enuresis at night only.

• Diurnal enuresis: Enuresis during the day only.

• Nocturnal and diurnal enuresis: Enuresis during both day and night.

The pathophysiology of enuresis is not completely clear; however, immaturity on the part of the autonomic nervous system that controls the bladder is present in the vast majority of cases. Only 20% of children with enuresis have a psychodevelopmental disorder (lower intelligence quotient or behavioral disorder). Secondary enuresis is often associated with a stressful environmental event. Urinalysis is the only mandatory investigation for nocturnal enuresis.

Treatment: the therapeutic approach is still based on empirical data. Therapy is aimed at alleviating the symptoms of nocturnal enuresis rather than at curing the condition.

A behavior-modification program is the treatment of choice, including buzzer/bell and pad, positive reinforcement, charting progress to increase confidence and self-esteem, urinating before bedtime, avoiding liquids after the evening meal, and avoiding psychological trauma through blame or belittling the child.

Complete cystometric evaluation is incorrect. Cystometric analysis is used to evaluate the bladder's capacity to contract and expel urine.

Intravenous pyelography (IVP) is incorrect. IVP refers to a series of X-rays taken of the kidneys, their collecting or drainage system (the ureters), and the bladder. It is done to locate a suspected obstruction to the flow of urine through the collecting system.

Renal ultrasound is incorrect. If enuresis also occurs in the daytime or if urinary flow is small or interrupted, a renal ultrasound and a careful neurologic examination are indicated.

Urine culture is incorrect. Urine culture may be appropriate, but is not most important. Urine culture is useful mainly when history, physical examination, or both suggests infection.
Correct answer:
Refer the patient for a transrectal ultrasound of the prostate and order a PSA level.

Explanation
The correct response is to refer the patient for a transrectal ultrasound of the prostate and order a PSA level.

The clinical picture is suggestive of prostate cancer. Signs and symptoms include those similar to benign prostatic hyperplasia (BPH) (e.g., urinary frequency, urinary hesitancy, nocturia, hematuria, and difficulty achieving erections). Most patients are asymptomatic. Prostate cancer may manifest as focal nodules or areas of induration within the prostate. Modern transrectal ultrasound provides high-definition images of the prostate and guides biopsy. Measurement of the PSA is useful in detecting and staging prostate cancer.

Serum acid phosphatase would not be useful since it is found in many organs. A prostatic acid phosphatase would be more specific in diagnosing prostate cancer.

Since a nodule was found in this patient, it needs to be investigated further; reassuring the patient would be considered an insufficient medical practice.

Prazosin is an alpha-blocker used in the treatment of BPH. BPH usually results in a smooth, firm, elastic enlargement of the prostate, which is not seen in this patient.

Norfloxacin is an antibiotic used in the treatment of urinary tract infections. Signs and symptoms of a UTI include painful urination, increased frequency, and an odd smell to the urine. Urinalysis may show positive leukocyte esterase, nitrates, and blood, with WBCs and bacteria on microscopic examination.
Correct answer:
Increased intake of fluids

Explanation
This patient has passed calcium oxalate stones in his urine. Increasing his intake of fluids will help prevent future episodes of nephrolithiasis. At least 2 liters/day of fluid intake is suggested to prevent recurrent nephrolithiasis. Increased intake of water, coffee, and beer will all lead to decreased urine concentration of stone-forming solutes; alcoholic beverages inhibit the action and secretion of anti-diuretic hormone, leading to decreased urine solute concentration. In addition, reducing the intake of oxalate-rich foods, such as rhubarb, green leafy vegetables, chocolate, tea, liver, nuts, and seeds, is recommended.

Crystals form in urine when the urine is supersaturated with crystal-forming solutes such as calcium, phosphate, and uric acid. Some patients over-excrete solutes, while others drink inadequate amounts of fluids to keep solutes dissolved. Stones also occur when the urine is infected with urea-splitting bacterium (Proteus). Here, urea is broken down into ammonia and bicarbonate, which then forms ammonium hydroxide and bicarbonate, the components of struvite stones. Struvite stones consist of a triple phosphate of calcium, magnesium, and ammonium.

Certain stone inhibitors, such as pyrophosphate, citrate, and magnesium, prevent crystal growth. In patients who have low levels of these inhibitors, stones are more likely to form. We do not know if this patient is deficient in urinary stone inhibitors, only that he passed calcium oxalate stones.

24-hour urine collections, preferably 2 samples drawn 6 weeks apart, are recommended to assess urinary citrate excretion. Decreased intake of oranges (being a type of citrus fruit) will likely decrease urinary citrate levels. This modification will be of little benefit if his urine citrate levels are normal and may be detrimental if his levels are low.

Increased intake of liver is not recommended; liver is an oxalate-rich food.

Increased sodium is not advised in a patient who is prone to developing urinary calcium stones. Increased sodium intake leads to increased calcium excretion, which may promote further calcium stone formation. Increased protein intake is not recommended for patients with risk or recurrent renal stones and should be limited to less than 80 g/day.

Nephrolithiasis is a common problem, affecting some 2-9% of the population. Without preventative treatment, 50% of patients having an episode of nephrolithiasis will likely have recurrent episodes over the next 10 years.

Because of its likely recurrence, measures to prevent recurrent nephrolithiasis (such as increasing water intake, decreasing sodium intake, and moderating calcium intake) are all important in patients who have documented calcium phosphate stones.
Correct answer:
Abdominal examination, including digital rectal exam

Explanation
The portion of your examination on this patient that would be the most crucial is the abdominal examination, including digital rectal exam (DRE), because a male patient in this age group is at risk for both benign prostatic hyperplasia (BPH) and prostate cancer. The lower urinary tract symptoms listed are indicative of BPH, as is the minimally elevated prostate-specific antigen. It would be important to rule out prostate cancer prior to treatment of the BPH. Prostate cancer screening includes a DRE, which is one reason that abdominal examination, including digital rectal exam (DRE), is the correct answer. A healthcare provider is also able to determine whether a patient's prostate is enlarged by doing a DRE, which is an extension of the abdominal examination. Suprapubic palpation of the bladder during the abdominal examination may indicate a large amount of retained urine secondary to BPH.

Percussion of costovertebral angle tenderness (CVAT) is typically used to detect discomfort related to hydronephrosis. Hydronephrosis could be present secondary to obstruction of the urinary tract by various causes. It is true that extreme cases of BPH can cause hydronephrosis and therefore CVAT. This does not, however, make percussion for CVAT a more important component than abdominal examination and DRE. The latter is used for diagnosis, and the former can help diagnose a complication.

Scrotal examination should be part of any genitourinary examination of a male patient, but it is not needed to make this patient's diagnosis. The lower urinary tract symptoms described are not symptoms of any scrotal abnormality. They are also not symptoms of any hepatic abnormality, so liver percussion would not be imperative in this case.
Correct answer:
Functional incontinence

Explanation
This patient most probably has functional incontinence secondary to her CVA. With functional incontinence, a person is usually aware of the need to urinate, but because of a physical or mental reason are unable to get to a bathroom. This patient cannot walk to the toilet independently because of her reduced mobility, and she cannot communicate the need to urinate because of the impairment of both expressive and receptive skills.

Diabetic cystopathy is a form of autonomic neuropathy. It is a chronic condition caused by selective damage to autonomic afferent nerves, leaving motor function intact, but impairing the sensation of bladder fullness; therefore, it results in decreased urinary frequency, overdistension of the bladder, and overflow incontinence. It is unlikely that your patient has overflow incontinence; her incontinence started after the admission, and post-void residual volume is less than 100 ml.

Overactive bladder (also known as urge incontinence) is a chronic condition characterized by the involuntary loss of urine preceded by a strong urge to void; it occurs whether or not the bladder is full. This patient had no incontinence before the admission; therefore, it is unlikely that she has an overactive bladder.

In general, renal insufficiency is an unlikely cause of urinary incontinence.

Normotensive hydrocephalus is a chronic condition characterized by gait disturbance, urinary incontinence, and dementia. She had no such symptoms before the admission.
Correct answer:
Acute cystitis

Explanation The symptoms of high fever with chills, nausea, vomiting, and back pain with tenderness in the renal angle are classic for pyelonephritis. It is a common condition in young women. The common organisms are gram negative, for example E.coli, klebsiella, proteus, enterobacter, and pseudomonas. Gram positive bacteria, like staphylococcus aureus and enterococcus fecalis, may also be seen. The usual mode of infection is ascent from the lower urinary tract, except for staphylococcus aureus, which is hematogenously spread. Leukocytosis with a left shift and abnormal urine with pyuria and bacteriuria confirm the condition. Absence of pyuria should be an indication to look for an alternative diagnosis. Hematuria may also be present. Blood and urine cultures should be done. Imaging may be needed in complicated cases, in which scenario an ultrasound may reveal hydronephrosis due to obstruction from a calculus or other causes. It is generally recommended that all males with acute pyelonephritis undergo imaging with ultrasound or CT scan, since such an infection is usually associated with an anatomical abnormality like enlarged prostate, etc. A long urethra and absence of organisms residing in vagina makes it unusual for men to have a urinary infection with a normal anatomy. Treatment should be started empirically without waiting for culture results, since they are usually not available immediately, and as they become available, antibiotics may be changed accordingly. Urine gram stain, which is available right away, may be a useful tool to direct antibiotic treatment. Indications for hospitalization include vomiting, pregnancy, HIV disease, diabetes, impending septic shock with unstable vitals, and other comorbidities like renal failure, post transplant, etc. It should be treated with oral fluoroquinolone or trimethoprim-sulfamethoxazole for mild to moderate disease and IV ceftriaxone or a fluoroquinolone for hospitalized patients, to be substituted with oral antibiotics after improvement in symptoms. Total duration of antibiotics should be 10-14 days. Prognosis is usually good if diagnosis is prompt, treatment appropriate, and complications absent.
Acute cystitis is a milder disease, which is more common in women than men due to a short urethra and proximity to vagina with its abundance of micro-organisms. About 50-60% adult women have had a urinary tract infection in their lives at some point. 10% postmenopausal women also have been found to get these infections. Coitus seems to be a predisposing factor, and symptoms quite often arise after sexual intercourse (honeymoon cystitis). The offending organisms include gram negative bacteria, such as E.coli, in 80-85% cases in women; it is also common in men. Most of the other cases in women are due to staphylococcus saprophyticus, though this is uncommon in case of males. This is a coagulase negative staphylococcus, which is normally considered benign but is actually a true urinary pathogen and should not be ignored. Rarely, klebsiella, proteus, enterococci, etc. may be isolated. Symptoms include low grade fever, dysuria, urgency, increased frequency of urination, and suprapubic abdominal pain. Occasionally women may have gross hematuria. There is suprapubic tenderness on examination without costovertebral angle tenderness. Urinalysis shows pyuria, bacteriuria, and hematuria. Hematuria is absent in female patients with urethritis and vaginitis, which can cause similar symptoms and can be used to differentiate the conditions. Urine culture is usually positive for the causative organism. Treatment is based on culture reports. Uncomplicated cystitis in women can be treated with a 3-day course of trimethoprim-sulfamethoxazole, trimethoprim alone, fluoroquinolone, or cephalexin. A 7-day course of nitrofurantoin is also adequate. Men should be evaluated for underlying conditions since uncomplicated cystitis is uncommon in males. A 7-day course is recommended even for uncomplicated cases in men.

Acute gastroenteritis, or food poisoning, has a similar picture but without costovertebral angle tenderness. Diffuse abdominal pain and watery diarrhea are the predominant symptoms. Fever may be low grade or high grade. UA is usually normal.

Acute salpingitis, or pelvic inflammatory disease, is characterized by lower abdominal pain and tenderness, abnormal vaginal discharge and/or bleeding, dyspareunia with adnexal tenderness, and cervical motion tenderness on a pelvic examination. An acute episode may present with high fever and chills, profuse vaginal discharge, and severe lower abdominal pain. Leukocytosis is found in less than 50% patients; UA is mostly normal, and culture of the vaginal fluid should be done. Treatment is with broad spectrum antibiotics.

Acute diverticulitis is usually left sided and manifested by left lower quadrant abdominal pain and tenderness with diarrhea and occasionally low grade fever without chills. Leukocytosis may be present with sterile pyuria sometimes. The patient does not have back pain or costovertebral angle tenderness and seems well hydrated. Treatment is with ciprofloxacin and metronidazole for 7-10 days.
Correct answer:
Calcium

Explanation
The correct answer is calcium. Calcium stones are the most common type of renal calculi and can be further characterized as either calcium oxalate or calcium phosphate stones. Calcium oxalate stones make up about 60% and calcium phosphate stones make up about 20%, which results in calcium stones being about 80% of stones overall. Geography, fluid intake, and diet can all influence stone formation, but metabolism and genetics can also play a role. Absorptive hypercalciuria, renal hypercalciuria, and resorptive hypercalciuria can all result in calcium stone formation. Hyperuricosuria, gout, hyperoxaluria, and hypocitraturia are all other causes of calcium calculi.

Uric acid is the not the correct answer, as this is not the most common type of renal calculus. Uric acid stones make up about 10% of stones in the United States. Hyperuricosuira and/or a urinary pH less than 5.5 are the 2 most common causes of uric acid stones. Gout, increased turnover of nucleic acids (such as in polycythemia or psoriasis), increased purine intake, and alcohol consumption are all causes of hyperuricosuria and can therefore put a patient at risk for uric acid stones.

Struvite is not the correct answer, as this is not the most common type of renal calculus. Struvite stones make up about 7% of total renal calculi. Urinary tract infections secondary to the presence of urea splitting organisms can result in the formation of struvite stones. Klebsiella, Proteus, Staphylococcus, and Pseudomonoas produce urease. Urease breaks down urea and aids in the formation of ammonia. The ammonia then undergoes hydrolysis, which results in alkaline urine and reduced solubility of struvite, as well as urine that is supersaturated in struvite.

Cystine is not the correct answer, as this is not the most common form of renal calculi. Cystine stones make up about 3% of total renal calculi. Cystine stones form due to an autosomal recessive disorder in the metabolism of cystine, which leads to cystinuria. Once the urinary saturation of cystine is more than 250 mg/L, cystine stones can start to form.

Magnesium is not the correct answer, as this is not a type of renal calculi. In fact, magnesium has been known to be preventative of stone formation and is, therefore, a component in a lot of renal calculi prevention measures. Hypomagnesuria, usually dietary in nature, is a known risk factor for renal calculi formation. Maintaining urine magnesium about 50 mg/day is preventative.