Pathoma Chapter 10 GI
Terms in this set (96)
What is an apthous ulcer?
Stress ulcer - characterized by a gray base of granulomatous tissue surrounded by erythema
Recurrent apthous ulcers
Where does HSV-1 lay dormant?
Ganglia of trigeminal nerve
What are two precursor lesions to oral squamous cell ca?
Erythroplakia and leukoplakia
Leukoplakia vs. hairy leukoplakia
White plaque that cannot be scraped away (premalignant)
Hairy leukoplakia is always seen on lateral tongue, seen in immunocompromised individuals secondary to EBV induced hyperplasia (not premalignant)
Vascularized leukoplakia from angiogenesis - premalignant
What are the more serious complications associated with mumps?
Orchitis (especially in teens), pancreatitis, and aseptic meningitis
Why is there elevated serum amylase in mumps infection?
Because it affects parotid glands and can also cause pancreatitis
Sialadenitis and common causative organism
Inflammation of the salivary gland usually secondary to sialolithiasis (stone), leading to s. aureus infection
This benign tumor arises in the parotid at the angle of the jaw. It is composed of __ and __ tissue (biphasic tumor).
Stromal and epithelial
High rate of recurrence
This is a benign tumor arising in the parotid gland with a lymph-node like stroma
This is a malignant tumor arising in the parotid composed of mucous and squamous cells. What is the usual presenting sign?
Facial nerve damage
If a newborn presented with vomiting, polyhydramnios, abdominal distention, and aspiration, what would you think of?
Plummer-Vinson syndrome - 3 symptoms
Severe iron deficiency anemia
Beefy red tongue (atrophic glossitis)
Why is a Zenker diverticulum a false diverticulum?
It only involves part of the wall, in this case the the mucosa outpouches into the muscular wall
Where do Zenker diverticuli usually arise?
Above the upper esophageal sphincter - junction of esophagus and pharynx
Mallory-Weiss tears usually occur where?
Boerhaave syndrome - how can you tell that air has entered the mediastinum?
Subcutaneous emphysema - air bubbles under the skin, usually around the neck area, feel like "rice crispies"
What is the venous drainage of the esophagus? What vein is backed up in esophageal varices from portal HTN?
Most drains via azygous vein into SVC, some drains via L gastric vein
The L gastric vein backs up and increases pressure in the esophageal veins, causing varices and painless bleeding
What is the pathology behind achalasia? What has been damaged? What is a common cause of the damage
Ganglion cells of the myenteric plexus have been damaged. Disordered motility with inability to relax LES
Idiopathic or 2' to Trypanosoma cruzi - Chagas disease
What gives a "bird beak" sign on barium swallow?
Where is the myenteric plexus located?
Between the inner circular and outer longitudinal muscular layers
Sliding hiatal hernia
Cardia of stomach enters the esophagus - "hourglass" appearance with LES as the center of the hourglass
Stomach herniates up next to the diaphragm - hear bowel sounds in lower lung
Not associated with GERD
If congenital can lead to lung hypoplasia
Esophageal adenocarcinoma vs squamous cell ca
Adenocarcinoma arises from pre-existing Barrett esophagus (West), involving the lower 1/3
Squamous cell is from irritation to mucosa (worldwide): lye, hot tea, alcohol and tobacco, esophageal webs, achalasia. Involves upper 2/3
Esophageal ca in the upper 1/3 will spread to __ lymph nodes, the middle 1/3 to __, and the lower 1/3 to __
mediastinal or tracheobronchial
Celiac and gastric
Gastroschisis vs omphalocele
GS - malformation of anterior abdominal wall, intestines exposed
O - herniation of bowel into umbilical cord - intestines covered by peritoneum and amnion
Presenting symptoms of pyloric stenosis
Presents around 2 weeks after birth
Projectile nonbilious vomiting
Olive-like mass in abdomen
What stomach cells produce the mucin layer?
Curling ulcer vs. Cushing ulcer
Curling - from burns - dec volume leads to dec blood supply
Cushing - inc intracranial pressure overstimulates the vagus nerve and acid is overproduced
Why do NSAIDs cause ulcers?
They dec PGE2 - which dec acid production, inc blood flow, stimulate bicarb and mucous production
Receptors for acid production on the parietal cells can be stimulated by 3 things:
Chronic autoimmune gastritis is a type __ hypersensitivity, the cells being destroyed are __. The regions affected are
Fundus and body
Clinical features of chronic autoimmune gastritis
Atrophy and intestinal metaplasia
Achlorhydria with inc gastrin and G cell hyperplasia
Megaloblastic (pernicious) anemia due to loss of intrinsic factor (B12)
Where are G cells located?
What kind of cancers does chronic h. pylori gastritis increase risk for?
Adenocarcinoma (intestinal type)
Chronic autoimmune gastritis vs chronic h. pylori gastritis - affected sites
Autoimmune has atrophy of fundus and body with hyperplasia of the antrum
H pylori affects the antrum predominantly
What is a MALT lymphoma?
Mucosa associated lymphoid tissue - AKA extranodal/post-germinal center/marginal zone B cell lymphoma - the marginal zone only forms when there is chronic inflammation
Gastrin secreting tumor of the pancreas (can be assoc. with MEN I)
The most common duodenal ulcers are anterior. Posterior ulcers can cause what 2 complications?
Bleeding from gastroduodenal artery
Gastric ulcers are most commonly located __. Where do they bleed from?
Lesser curvature of the antrum; L gastric artery
Benign vs malignant ulcers (caused by intestinal type gastric ca)
Benign are punched out, small (<3cm), and sharply demarcated
Malignant - large and irregular with heaped up margins
Intestinal vs. Diffuse type of gastric ca
Intestinal - more common, presents as large ulcer with heaped up margins, lesser curvature of antrum
Diffuse - Signet ring cells - desmoplasia resulting in linitis plastica
What are the risk factors for intestinal type gastric ca?
Intestinal metaplasia from H. pylori and autoimmune gastritis
Nitrosamines in smoked foods
Type A blood
Presenting signs of gastric ca
Early satiety, anemia
Leser-Trelat sign - explosion of seborrheic keratoses
Virchow node (left supraclavicular)
Metastases of gastric ca
Intestinal: Sister Mary Joseph nodule - periumbilical
Diffuse: Krukenberg tumor (bilateral ovaries)
Where would you see a "double bubble" sign on xray?
Duodenal atresia - distention of both the stomach and duodenum
Duodenal atresia is associated with this developmental defect
What is the only true diverticulum?
Meckels - all 3 layers
How does a Meckel's diverticulum arise?
The vitelline duct, which transfers nutrients from yolk sac to midgut, fails to involute fully
What is the rule of 2's for a Meckel's diverticulum?
2% of population
2 inches long
within 2 feet of ileocecal valve
first 2 years of life
Why would a Meckel's diverticulum present as bleeding?
Contains heterotopic gastric mucosa, which produces acid and damages the small bowel
Where are the most common locations for a volvulus, by age group?
Cecum (young adults)
What are the leading edges in intussusception, by age group?
Lymphoid hyperplasia of terminal ileum from infection (children)
Transmural vs. mucosal infarction of small bowel
Transmural - entire wall - due to thrombosis of SMA or mesenteric vein
Mucosal - from marked hypotension
Congenital lactase deficiency is autosomal __. Acquired lactase deficiency arises with __ or __.
Age; temporarily after GI infection
Celiac disease is associated with HLA __ and __
DQ2 and DQ8
Dermatitis herpetiformis is due to
Celiac disease - IgA deposition at tips of dermal papillae
What are the 3 types of Abs in celiac disease?
Anti-endomysium (connective tissue around muscle fibers)
What are the findings in celiac disease on light microscopy? What area of the small bowel is primarily affected?
Flattening of villi and hyperplasia of crypts
Refractory celiac despite good dietary control would lead you to suspect
Small bowel ca and T cell lymphoma (EATC - enteropathy associated T cell lymphoma)
Affected areas in tropical sprue vs. celiac
Celiac - duodenum
Sprue - jejunum and ileum (present with secondary B12 or folate deficiency)
Where are B12 and folate absorbed?
Folate - jejunum
B12 - ilieum
(Folate is absorbed First)
What do the macrophages stain + for in Whipple disease?
Pathogenesis of Whipple's disease
Foamy macrophages full of t. whipelli organisms are found in lamina propria - compress lacteals and chylomicrons cannot be transferred from enterocytes to lymphatics - fat malabsorption/steatorrhea
What sites can Whipple's disease involve?
Abetalipoproteinemia is deficiency of __ and __, which are needed for
B48 (needed for chylomicrons)
B100 (needed for VLDL and LDL)
Carcinoid tumor of small bowel stains positive for
What is found in serum and in urine in a carcinoid tumor?
Serotonin - usually doesn't reach systemic circ because it goes through portal circ first and is metabolized by liver
5-HIAA - metabolite of serotonin excreted in urine
What is carcinoid syndrome and carcinoid heart disease? Why does carcinoid heart disease only affect the R heart
Carcinoid syndrome - serotonin in systemic circ.
Bronchospasm, flushing, diarrhea
Heart dx - valvular fibrosis (R side only) leading to tricuspid regurgitation, and pulmonic stenosis
Lungs have MAO, so serotonin never reaches L heart
What causes obstruction of the appendix, by age group?
Children - lymphoid hyperplasia
Adults - fecalith
Where is McBurney's point?
1/3 the distance from superior iliac spine to umbilicus
What intestinal abnormalities are associated with Down's syndrome?
Duodenal atresia and Hirschsprung disease
Hirschsprung disease pathology
Failure of ganglion cells from the neural crest to descend into myenteric and submucosal plexus, leading to massive dilatation (megacolon)
What are the two nerve plexi in the gut? Where are they located? What do they each regulate?
Myenteric (Auerbachs) - between inner circular and outer longitudinal muscle layers - motility
Submucosal (Meissner's) - submucosal - secretions, absorption, blood flow
UC vs. Crohn's:
Calcium oxalate stones
Primary sclerosing cholangiitis
Full thickness of gut wall
What are the inflammatory hallmarks of UC and Crohn's, respectively?
UC - Crypt abscesses with neutrophils
Crohn's - Lymphoid aggregates with granulomas
Smoking can actually be a protective factor in
UC vs. Crohn's:
Mucosal/submucosal involvement only
"lead pipe" sign
Crohn's primarily affects this portion of the gut, and usually spares this portion
Terminal ileum; rectum
Where do colonic diverticula usually arise?
Sigmoid colon (LLQ) - where vasa recta traverse the muscularis propria - weak point
High wall tension in the L colon can lead to __. High tension in R colon can lead to __.
Hereditary hermorrhagic telengiectasia is autosomal __. Results in
Thin walled blood vessels in mouth and GI
What is the watershed area of the SMA, and the place most likely to get ischemic colitis? When will pain present?
After eating (more demand for blood supply)
Hyperplastic vs adenomatous polyps
Hyperplastic - hyperplasia of glands, serrated appearance, no malignant potential
Adenomatous - neoplastic proliferation of glands, premalignant
Hyperplastic polyps usually arise in the
L colon (rectosigmoid)
What is the adenoma-carcinoma sequence?
1st mutation - APC double knockout or germline mutation
2nd - K-ras and formation of polyp
3rd - p53 and inc expression of COX, progression to ca
What common drug can impede progression from colonic adenoma to carcinoma?
Aspirin - COX inhibitor
FAP is due to mutation of __ gene on chromosome __
FAP with osteomas is called __
FAP with CNS tumors (medulloblastoma and glial) is called __
Peutz-Jeghers syndrome is autosomal __. It presents with
Hamartomatous (benign) polyps in GI
Hyperpigmentation on lips, oral mucosa, and genitals
Inc risk for colorectal, breast, and gyn cancer
Colorectal ca arising from the adenoma-carcinoma sequence is usually on the __ side. Arising from the microsatellite instability pathway is on the __. Which presents more with napkin-ring lesions and obstruction? Which presents more with raised lesions and occult bleeding?
What is the microsatellite instability pathway for progression to colorectal ca?
Inherited defects in DNA MMR enzymes (HNPCC)
HNPCC increases risk for these types of cancers
colorectal, ovarian, endometrial
Pt with strep. bovis endocarditis, think
What is a tumor marker useful for following response and recurrence of colorectal ca?
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