Term
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Definition
| associated with achalasia. in achalasia, abnormalities of nerve components of the esophagus contribute most significantly to the clinical problem. particularly loss of ganglion cells in the myenteric plexus or damage caused by intracytoplasmic hyaline or spherical eosinophilic inclusions or lewy bodies. |
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Term
| what is the Heller Myotomy? |
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Definition
| laproscopic procedure done to surgically cut open the lower esophageal sphincter. |
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Term
| what are type A and type B gastritis? |
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Definition
| type A = autoimmune gastritis, involves fundus and body of stomach. type B = h. pylori, involves antrum |
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Term
| achalasia can be secondary to what condition? |
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Definition
| chagas disease (t. cruzi destroys the myenteric plexus) |
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Term
| what do we call diverticulum occurring in the upper esophagus |
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Definition
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Term
| what do we call diverticulum occurring in the middle esophagus |
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Definition
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Term
| what do we call diverticulum in the lower esophagus |
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Definition
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Term
| histological hallmarks of reflux esophagitis |
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Definition
| basal cell hyperplasia and lamina propria papillae that reach the top third of the epithelial layer |
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Term
| how do we differentiate low grade vs high grade dysplasia in a biopsy of barrett's esophagus? |
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Definition
| low grade = dysplastic nuclei still basal in location (can still see mucin on top); high grade = dysplastic nuclei no longer basal in location (cannot see mucin anymore, see mitotic figures)) |
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Term
| how is adenocarcinoma in situ diagnosed histologically? |
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Definition
| back to back glands without intervening stroma (cribiform pattern) |
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Term
| which part of the esophagus is normally affected by esophageal adenocarcinoma? squamous cell carcinoma? |
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Definition
| adenocarcinoma = distal third; squamous cell = middle third |
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Term
| what are the 3 gross morphologic patterns observed in esophageal squamous cell carcinoma? |
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Definition
| protruded, flat, excavated |
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Term
| what is the toxin associated with h. pylori? |
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Definition
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Term
| 2 most common places to find peptic ulcer disease |
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Definition
| first portion of the duodenum and the gastric antrum |
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Term
| what is the pathological basis of menetrier's disease and what is the etiology? |
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Definition
| etiology = excessive secretion of TGF-a. pathology = hyperplasia of surface mucous cells, gastric gland atrophy, protein loss |
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Term
| describe the histology of inflammatory polyps and what causes them |
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Definition
| hyperplastic surface epithelium, cystically dilated foveolar glands, inflammatory cells, edema. most often seen with chronic gastritis, non-neoplastic, result from chronic inflammation |
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Term
| what is the histology of fundic gland polyps and what causes them? |
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Definition
| histology: cystically dilated, irregular gastric glands lined by parietal and chief cells. d/t use of proton pump inhibitors (low acid, increse in gastrin with resulting glandular hyperplasia) |
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Term
| 4 gross presentations of gastric carcinoma? |
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Definition
| exophytic, flat, excavated, linitis plastica (stomach so infiltrated by malignant cells that it becomes rigid and thickened and is less distensible than the normal stomach - leather bottle stomach) |
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Term
| what are the 2 microscopic categories of gastric carcinoma? |
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Definition
| 1. intestinal type - dysplasia as an important antecedent factor, arises from gastric cells that have first become intestinal metaplasia, arises from chronic gastritis/h.pylori colonization, seen as glands on top of glands. 2. diffuse type - arise de novo (no association with chronic gastritis or h. pylori), no evolution thru dysplasia, no intestinal hyperplasia, looks like innumerable single malignant mucus cells that do NOT form glands (signet-ring cells) |
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Term
| how do the majority of gastric cancers start? |
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Definition
| sporadic (1-3% are hereditary = diffuse type) |
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Term
| what is the mutation seen in about 30% of familial gastric cancers? |
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Definition
| germline mutation in one allele of the E-cadherin gene (CDH1) - mutational analysis suggested for people with at least two relatives with diffuse gastric cancer, one of whom is diagnosed before age 50) |
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Term
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Definition
| (metastatic tumor of gastric origin) supraclavicular lymph node with metastatic tumor |
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Term
| what is a krukenberg tumor? |
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Definition
| (metastatic tumor of gastric origin) metastatic tumor to one or both ovaries |
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Term
| what is sister mary joseph nodule? |
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Definition
| (metastatic tumor of gastric origin) subcutaneous tumor deposit in the periumbilical region |
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Term
| how do we distinguish between a leiomyoma and a gastrointestinal stromal tumor? |
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Definition
| stain with desmin, which is a smooth muscle marker. will stain in a leiomyoma and not in GIST (mesenchymal/stromal cell tumor) |
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Term
| where are GIST masses normally located? |
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Definition
| GIST tumors can be anywhere in GI tract but more than 50% in stomach. they are SUBMUCOSAL or INTRAMUSCULAR masses |
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Term
| what do the cells in GIST look like? |
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Definition
| either spindled (long, thin), epithelioid (rounded, lots of cytoplasm) or combination of both |
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Term
| GISTS originate from what? |
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Definition
| interstitial cells of cajal (found in muscularis propria, they are the gastric pacemaker cells) |
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Term
| what are the possible mutations giving rise to GISTs? |
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Definition
| gain-of-function mutations of the gene encoding the tyrosine kinase c-KIT (CD117) (75-80%); mutation in platelet-derived growth factor receptor alpha (8%) |
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Term
| smoking protects against what GI disease? |
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Definition
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Term
| what mutation is seen in 15% of patients with crohns disease (and 50% of those with fistulizing crohns disease) |
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Definition
| nucleotide oligomerization domain (NOD2) gene |
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Term
| what are 2 classic rashes associated with IBD? |
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Definition
| erythema nodosum; pyoderma gangrenosum |
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Term
| what are the 3 major patterns of presentation in crohns disease? |
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Definition
| disease in the ileum; disease confined to the small intestine; disease confined to the colon |
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Term
| how do we distinguish between IBD and infection? |
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Definition
| biopsy --> IBD would have architectural distortion and infection would have architecture intact with lots of neutrophils |
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Term
| what is the drug treatment regimen for IBD? |
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Definition
| mesalamine for mild to moderate IBD; then corticosteroids (prednisone) but can only be used for 2-3 months; then steroid sparing meds like 6-mercaptopurine or azothioprine; metronidazole for fistulizing crohn's; anti-TNFa like infliximab... |
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Term
| if a patient has no family hx of colon cancer, what is their screening regimen? |
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Definition
| (6% risk) screen starting at age 50 every 10 years with colonoscopy (every 5 years if african american) |
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Term
| if a pt has + fam hx for colon cancer, what is their screening regimen? |
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Definition
| (12% risk) start at age 40 (or 10 years prior to family member diagnosis) every 5 years |
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Term
| what is the screening in someone who has a family history of familial adenomatous polyposis? |
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Definition
| sigmoidoscopy starting at age 12 every 1-2 years (pt will develop rectosigmoid polyps by age 15-16) |
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Term
| what is the proper screening for someone with a fam hx of hereditary non-polyposis colorectal cancer? |
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Definition
| colonoscopy @ 25 years old, every 1-2 years |
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Term
| what are the 3 groups of bac found in the colon? |
|
Definition
| bacteroides (gram - anaerobic), firmicutes (gram +), proteobacteria (gram -) |
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Term
| what type of bacterial flora do we see in the esophagus? |
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Definition
| streptococcus (39%), bacteroides (17%), veilonella (14%) |
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Term
| what floral organisms found in the stomach? |
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Definition
| not many d/t acidity. lactobacilli, fusobacterium. h. pylori |
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Term
| which floral organisms can we find in the small intestine? |
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Definition
| few d/t acidity from stomach. in proximal bowel find lactobacillus and helicobacter (like stomach); distal small intestine find anaerobes and enterobac (like colon) |
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Term
| main organisms in the colon? |
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Definition
| bacteroides, fusobacterium, bifidobacterium and clostridum (also enterobac) |
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Term
| what does fusobacterium cause? |
|
Definition
| pulmonary inf. (and gingivitis?) |
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Term
| what is the one pathogenic species of bifidobacterium? |
|
Definition
| b. dentium --> advanced gingivitis |
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Term
| what infections do proteus spp cause? |
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Definition
| urinary tract and other hospital acquired infections |
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Term
| how do we differentiate proteus vulgaris from proteus mirabilis? |
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Definition
| indole test - only p. vulgaris positive |
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|
Term
| which bac lead to urinary stones? |
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Definition
| proteus and morganella (produce potent urease -- urinary stones) |
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Term
| what are the 4 types of cells that make up the epithelial lining of the smsall intestine? |
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Definition
| 1. epithelial absorptive cells located at the tips of the villi (reabsorb na and h20) 2. epithelial secretory cells localized mainly in the villous crypts (secrete Cl and H20) 3. paneth cells located in the crypt epithelium (secrete mucin, cryptidins and defensins) 4. enteroendocrine cells located in the crypts (release peptide hormones from granules to influence bowel motility and absorption of nutrients) |
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Term
| 4 fundamental processes that result in malabsorption and diarrhea |
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Definition
| lack of normal intraluminal digestion, increased intestinal secretion induced by secretogogues, reduced absorptive surface area, altered intestinal motility |
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Term
| most nutrients (carbs, proteins, fats) absorbed where in the small intestine? |
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Definition
| first 100 cm (duodenum and jejunum) |
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Term
| calcium, iron, folate, fat-soluble vitamins absorbed where in the sm intestine? |
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Definition
| proximally (duodenum and proximal jejunum) |
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Term
| B12 and zinc absorbed where in the sm intestine? |
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Definition
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|
Term
| where does bile acid absorption take place in the small intestine? |
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Definition
| active transport in terminal ileum (some passive transport in jejunum and proximal ileum) |
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Term
| how do we test for fat in the stools? |
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Definition
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|
Term
| how do we test for pancreatic insufficiency? |
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Definition
| 1. elastase level (pancreatic enzyme) 2. serum trypsinogen (released by pancreas in response to CCK) 3. secretin stimulation test (collect pancreatic fluid measure enz --> give secretin --> re-measure enz, should be 2-3x as high) |
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Term
| how do we test for protein loss in the stool? |
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Definition
|
|
Term
| how do we check for eosinophils in the stool? |
|
Definition
| wright stain or charcot leyden crystals |
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|
Term
| what causes damage to the sm intestinal cells in celiac disease? |
|
Definition
| cytokines released by T cells |
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|
Term
| what HLA classes are common in celiac disease? |
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Definition
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|
Term
| people with celiac disease are at increased risk for what? |
|
Definition
| lymphoma and small intestine adenocarincoma |
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Term
| where is injury localized to in celiac disease? tropical sprue? |
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Definition
| celiac disease injury localized to proximal small intestine (where gluten is concentrated); tropical sprue injury localized to distal small intestine |
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Term
| what do we look for histologically in crohn's disease vs ulcerative colitis? |
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Definition
| SAME FOR BOTH: crypt abcesses (neutrophil infiltrate in the crypts), chronic mucosal inflammation; CD: crypt destruction, lymphocyte infiltration, mucosal fibrosis, GRANULOMAS (50%), branched and distorted crypts, inflammation in ALL layers. UC: submucosa and mucosa involved, muscularis propria is spared, NO granulomas |
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Term
| what immunohistochemical staining do we do for carcinoid tumors? |
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Definition
| chromogranin A (stains for neuroendocrine cells) and synaptophysin (both positive in carcinoid tumor) |
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Term
| what is the carcinoid syndrome? |
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Definition
| complication of carcinoid tumor related to release of vasoactive substances into the systemic circ. sx: cutaneous flushing, sweating, bronchospasm, colicky abdominal pain, diarrhea, right-sided cardiac valvular fibrosis. (makes you suspect metastatic disease) |
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Term
| meissner's plexus located in the |
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Definition
|
|
Term
| auerbach's plexus (meyeners) located in the? |
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Definition
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|
Term
| what is the cause of hirschprung's disease? |
|
Definition
| (congenital colon problem) normal migration of neural crest cells from cecum to rectum arrested prematurely or when ganglion cells die. aka congenital aganglionic megacolon |
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Term
| who is affected by hirschprung's disease? |
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Definition
| infant (failure to pass meconium), children (severe constipation). males 4:1. 10% in down syndrome pts. |
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Term
| what is the characteristic microscopic appearance of pseudomembranous colitis? |
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Definition
| mucopurulent exudate (from superficially damaged crypts of the colonic mucosa) erupts from the crypts to form "mushroom clouds" that adhere to the damaged surface and coalesce to form the psuedomembrane. |
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Term
| what is a complication of pancolitis? |
|
Definition
| backwash ileitis (reflux of colonic inflam material into the terminal ileum) |
|
|
Term
| what is a rare but serious complication of ulcerative colitis |
|
Definition
| acute toxic megacolon. total or segmental colonic dilatation with loss of contractility and rapid clinical deterioration. muscle loses tone with stretching --> damage to myenteric plexus (in muscularis propria) --> colonic atony --> colonic wall progressively thins until blood supply is cut off (gangrene) or perforation occurs (peritonitis) --> medical emergency |
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Term
| describe juvenile polyps histologically |
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Definition
| mostly lamina propria and dilated cystic glands |
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|
Term
| histological hallmark of peutz-jeghers polyp |
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Definition
| normal colonic glands resting on a branching smooth muscle framework that arises from the muscularis mucosa |
|
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Term
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Definition
| mutation of the adenomatous polyposis coli gene (APC) mapped to chromosome 5q21 |
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Term
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Definition
| mutation in the DNA mismatch repair genes leading to microsatellite instability |
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|
Term
| first genetic pathway leading to colon cancer (APC/B-catenin) involves mutations in which genes? |
|
Definition
| APC (first hit, second hit) K-RAS, p53, SMAD2, SMAD4 |
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|
Term
| histologic hallmark of acute appendicitis |
|
Definition
| neutrophils in the muscularis propria of the appendix |
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|
Term
| "nocturnal acid breakthrough" associated with which medications? |
|
Definition
| PPI - do such a good job of decreasing acid in the stomach that theres no acid to activate the prodrug of the next dose. so meds stop working, pt experiences sx at night. help this by giving H2 blockers. |
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