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Adrenal Disorders (Shubrook)

Terms in this set (71)

what is the classic presentation of cushing's?
women of reproductive age >> men

central obesity, with peripheral muscle weakness
what labs would you order based on a differential of cushings?
Metabolic panel
DHEA suppression test
TSH
what is the most common cause of cushing's?
iatrogenic = exogenous steroids

prednisone, inhaled/topical glucocorticoids
what are the causes of too much ACTH causing Cushing's syndrome?
Pituitary adenoma producing ACTH = cushing's disease

ectopic ACTH secretion = small cell lung CA, bronchial carcinoid
what are the causes of too much cortisol causing Cushing's syndrome?
adrenal tumor
nodular adrenal hyperplasia
what are the first line tests to diagnose Cushing's syndrome?
Late night salivary cortisol
24-hour urinary cortisol
Low-dose dexamethasone test

at least 2 first line tests should be abnormal to diagnose Cushing's syndrome

(no single test done in isolation)
What is the Dexamethasone Suppression Test?
measure cortisol levels after administering dexamethasone (dexamethasone is a potent glucocorticoid that should suppress CRH/ACTH)
Low-dose dexamethasone suppression
differentiates if patient has Cushing's syndrome of any cause:
- if cortisol remains high (not suppressed), the pt has Cushing's syndrome
- will not suppress ACTH from a pituitary tumor

should be repeated
high-dose dexamethasone suppression
will suppress the ACTH
what do you predict the cause of Cushing's if there is high ACTH?
pituitary = ACTH-dependent Cushing's
what do you predict the cause of Cushing's if there is low ACTH?
adrenal = ACTH-independent Cushing's
what is the next step after determining ACTH-dependent Cushing's?
Pituitary MRI

CRH stimulation test
CRH stimulation test
will stimulate ACTH production from pituitary tumor

will not stimulate ACTH from ectopic or adrenal tumors
what is the purpose of high-dose dex test?
Differentiates between Cushing's disease (pituitary tumor) from other ACTH tumors
- will suppress ACTH from a pituitary tumor
- will not suppress ACTH from an ectopic tumor
what is the number one treatment of Cushing's syndrome?
remove the glucocorticoid
what is the first-line treatment of cushing's disease?
transsphenoidal surgery
what is the second line treatment of cushing's disease?
pituitary irradiation
what are the goals of Cushing's treatment?
Reverse the clinical manifestations by reducing cortisol secretion to normal
Eradicate any tumor threatening the health of the patient
Avoid permanent dependence upon medications
Avoid permanent hormone deficiency
treatment of ectopic ACTH causing cushing's
Surgical excision of tumor
Adrenal enzyme inhibitors = For non-resectable tumors
Glucocorticoid antagonists
treatment of primary adrenal tumor/hyperplasia causing cushing's
adrenalectomy
what medications can cause HTN and hypokalemia?
Thiazide diuretics
beta agonists
insulin
when is primary hyperaldosteronism suspected?
in people who have uncontrolled HTN with hypokalemia (no diuretic or other cause)
what is the most common cause of primary hyperaldosteronism?
Adenoma = Conn's syndrome
- usually benign, solitary nodules
what are other causes of primary hyperaldosteronism?
bilateral micronodular adrenal hyperplasia
familial
carcinoma
signs and symptoms of primary hyperaldosteronism
HTN
muscle weakness
lack of edema
lab findings of primary hyperaldosteronism
hypokalemia (<3.0)
hypernatremia
metabolica alkalosis

high plasma aldosterone
low plasma renin
what can be done to confirm primary hyperaldosteronism?
aldosterone suppression test (typically done in endocrine office)
what labs should be taken if suspecting primary hyperaldosteronism?
electrolytes
plasma and urine osmolality
renin
aldosterone
what is the treatment of primary hyperaldosteronism?
Adrenalectomy
Spironolactone if bilateral hyperplasia
Sodium restriction
secondary hyperaldosteronism
overactive renin-angiotensin system = kidney's perception of low IV volume
secondary hyperaldosteronism DDX
renal artery stenosis
chronic renal failure
CHF
nephrotic syndrome
cirrhosis
congenital adrenal hyperplasia (CAH) characteristics
autosomal recessive disorders

enzyme deficiencies that block cortisol/aldosterone synthesis

precursors shunted to synthesis of androgens

causes adrenal hyperplasia secondary to increased ACTH production
what is the most common CAH?
21-hydroxylase deficiency
21-hydroxylase deficiency
salt losing form = majority

newborn virilization

late onset: late childhood-adulthood
Labs diagnosing 21-hydroxylase deficiency
newborn screen

elevated 17-alpha hydroxyprogesterone (17-OHP)
what is the most common cause of chronic adrenal insufficiency?
suppression of HPA axis from prolonged exogenous glucocorticoids
what is the most common cause of chronic primary adrenal insufficiency?
Addison's disease = autoimmune destruction of the adrenal gland
what is the pathogenesis of primary adrenal insufficiency?
destruction of the adrenal gland
what are other causes of Addison's disease?
Infections
TB
amyloidosis
hemochromatosis
labs seen in addison's disease?
increased ACTH and melanocyte stimulating hormone (MSH) = hyperpigmentation

decreased aldosterone:
- hypnatremia
- hyperkalemia
- hypotension
what are the early, non specific signs of addisons disease?
Anorexia, weight loss, nausea, generalized abdominal pain, fatigue, weakness
Salt craving
Hyperpigmentation
Hypotension
what is the late sign of addison's disease?
presents as shock
secondary/tertiary adrenal insufficiency
Hypothalamic or Pituitary disease
Can occur alone or as part of Panhypopituitarism
Similar presentation to primary adrenal insufficiency, but don't see effects of low aldosterone
secondary/tertiary adrenal insufficiency labs
decreased CRH/ACTH => decreased cortisol
- Non-specific symptoms: weakness, fatigue, weight loss
- Unlike Addison's disease, not associated with hyperpigmentation (no MSH)

normal aldosterone
Adrenal insufficiency workup
Electrolytes can give you a clue
Serum cortisol levels low
Serum ACTH levels
ACTH Stimulation Test
ACTH stimulation test in primary adrenal insufficiency
ACTH levels are already high

cortisol level will not rise when cosyntropin administered
ACTH stimulation test in secondary adrenal insufficiency
ACTH levels low

cortisol levels will rise when cosyntropin administered
what glucocorticoids are used to treat chronic adrenal insufficiency?
Hydrocortisone/Prednisone (short acting)

Use the lowest glucocorticoid dose that relieves symptoms
Contraindication: Any active infection, especially Tuberculosis
what mineralcorticoids are used to treat chronic adrenal insufficiency?
Fludrocortisone (has both glucocorticoid and mineralcorticoid activity)

adjust dose until plasma renin activity normal
what are the emergency precautions in chronic adrenal insufficiency treatment?
lack of stress response to illness/surgery

2-3x maintanence glucocorticoid dose for 3 days (stress dose)

injectable glucocorticoid

medical alert bracelet
what are the causes of acute adrenal insufficiency (aka adrenal crisis)?
primary adrenal insufficiency

less commonly secondary adrenal insufficiency

abrupt withdrawal of exogenous glucocorticoids
what is the most common cause of adrenal crisis?
the first diagnosis of Addison's
what bacteria causes acute adrenal insufficiency?
infection with neisseria meningitidis => waterhouse friderichsen syndrome = failure of adrenal glands caused by bilateral hemorrhage secondary to sever bacterial infection

shock, DIC, widespread purpura
usually pediatric patients
what is the presentation of adrenal crisis?
shock = volume depletion, hypotension

nonspecific symptoms:
- N/V, abdominal pain
- weakness, fatigue, fever
- confusion, coma
- hypoglycemia
what is the most important first step in treating acute adrenal insufficiency?
IV fluids!: 1-3 L of normal saline depending on volume status; can add 5% dextrose if hypoglycemic
what are the next 2 steps of treating acute adrenal insufficiency?
glucocorticoids IV (dexamethasone, hydrocortisone) -- mineralcorticoid replacement not necessary

treat the cause of adrenal crisis (i.e. infection)
what is the most common tumor of adrenal medulla in adults?
pheochromocytoma
what can trigger pheochromocytomas?
pain, emotional upset, surgery

tyramine containing foods (aged cheeses, meats, fish, beer, wine, chocolate, bananas)
what is the classic triad of pheochromocytoma?
headache
sweating
tachycardia
what is the presentation of pheochromocytoma?
young to mid-adulthood HTN
what are the common locations of pheochromocytoma?
90% unilateral: more often R than L
- R adrenal tumors more likely to present with paroxysms of HTN
- L adrenal tumors more likely to be sustained hypertension
- bilateral pheos more common in syndromes
what endocrine neoplastic syndromes can pheochromocytoma be a part of?
MEN-2A
- Medullary thyroid cancer (95%-100%)
- Pheochromocytoma (50%)
- Hyperparathyroidism (35%)

MEN-2B
- Medullary thyroid cancer
- Pheochromocytoma
- Adrenal medullary hyperlasia
- Mucosal neuromas
what genetic syndromes can pheochromocytoma be a part of?
VHL disease, NF 1, Beckwith-Wiedemann syndrome
how are pheos diagnosed?
biochemical 1st
- 24 hour urinary fractioned catecholamines and metanephrines
- if elevated, image with CT or MRI
what is the treatment of pheochromocytoma?
surgical resection of tumor

preoperative: alpha first! = phenoxybenzamine, then long acting nifedipine (CCB), short acting nifedipine for paroxysms

alpha before beta blocker = prevents unopposed alpha stimulation that can cause worsening HTN
what is the incidence of incidentalomas?
common:
- 3% in middle age adults
- 10% in those > 60 y/o
- most are small and low density
what is the pheo paradox in incidentalomas?
4% of all incidentally discovered adenomas

half of pheochromocytoma in US are detected incidentally
how are incidentalomas evaluated?
biochemical first (like pheo): plasma fractionated free metanphrines => if metanphrines are >2x ULN high risk of pheo

could test for hyperaldosteronism and cushing's
if high need further eval
if low
- 3-5 cm close surveillance
- > 5cm probably should be resected
what is the sympathetic innervation of adrenals?
T8-T10
what is the anterior chapman's points of adrenals?
5-7cm above and 2-3 cm lateral to umbilicus
what is the posterior chapman's points of adrenals?
midway between the tips of the spinous process and transverse process of T11-T12
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