GI day 2

Question 1

tropical sprue

Answer 1

similar findings to celiac sprue, but responds to abx

- cause is unknown, but seen in residents of or recent visitors to the tropics

Question 2

whipple disease

Answer 2

• infection with tropheryma whippeli, treat with abx
• PAS + foamy macrophages in intestinal lamina propria
• Cardiac symptoms, Arthralgias, Neurologic symptoms
• most often occurs in older men
• Foamy Whipped cream in a CAN

Question 3

celiac sprue

Answer 3

• AI mediated intolerance of wheat leading to malabsorption and steatorrhea
• associated with HLA DQ2 and DQ8
• findings include anti-endomysial, anti-TTG an anti-gliadin Abs
• blunting of the villi and lymphocytes in he lamina propria
• decreased mucosal absorption that primarily affects the dist duo/prox jejunum
• mod increased risk for malignancy (T cell lymphoma)

Question 4

disaccharidase deficiency

Answer 4

• most common is lactase deficiency
• normal appearing villi, osmotic diarrhea
• lactose tolerance test: positive if administer lactose, get symptoms + glucose rises < 20mg/dL
• stool pH will also decrease

Question 5

abetalipoproteinemia

Answer 5

• decreased synthesis of apolipoprotein B –> inability to generate chylomicrons –> decreased secretion of cholesterol and VLDL into blood stream –> fat accumulation in enterocytes (otherwise normal architecture)
• presents in early childhood with FTT, steatorrhea, acanthocytosis (thorny projections from RBCs), ataxia and night blindness

Question 6

pancreatic insufficiency

Answer 6

• due to CF, obstructing cancer or chronic pancreatitis
• ADEK malabsorption
• increased neutral fat in stool, D-xylose testing normal

Question 7

crohn disease

Answer 7

• disordered response to bacteria
• skip lesions, esp affects the terminal ileum
• transmural inflammation, fistulas, cobblestone mucosa, creeping fat, bowel wall thickening, string sign, linear ulcers, fissures
• noncaseating granulomas
• diarrhea may or may not be bloody
• extraintestinal manifestations: migratory polyarthritis, erythema nodosum, ank spon, pyoderma gangrenosum, apthous ulcers, uveitis, kidney stones
• treat with corticosteroids, azathioprine, MTX, infilximab, adalimumab

Question 8

CRC from crohns

Answer 8

• young pts
• progresses from flat/non-polypoid dysplasia
• mucinous or signet rings
• develop early p53 mutations rather than APC
• distributed within the prox colon
• multifocal

Question 9

UC

Answer 9

• AI
• mucosal and submucosal inflammation only
• no haustra –> lead pipe appearance on imaging
• crypt abscesses and ulcers, bleeding, no granulomas
• malnutrition, sclerosing cholangitis, toxic megacolon, CRC
• pyoderma gangrenosum, erythema nodosym, ank spon, apthous ulcers, uveitis
• treat with ASA preps (sulfasalazine), 6-MP, infliximab, colectomy

Question 10

Zenker diverticulum

Answer 10

• not a true diverticulum
• cricopharyneal muscle dysfunction due to diminished relaxation leads to increased intraluminal pressure and herniation of the pharyngeal mucosa
• most common in elderly males, can lead to asp pneumo

Question 11

meckel diverticulum

Answer 11

• true diverticulum
• persistence of the vitelline duct that may contain ectopic-acid secreting gastric mucosa and/or pancreatic tissue
• melena, RLQ pain, intussusception, volvulus, or obstruction near the terminal ileum
• diagnose with pertechnetate study for uptake by ectopic gastric mucosa
• this is an example of ectopy, not metaplasia
• 5 2’s: 2 inches long, 2 feet from the ileocecal valve, 2% of the populaiton, commonly presents at 2 years old, may have 2 types of epithelia

Question 12

angiodysplasia

Answer 12

• tortuous dilation of vessels –> hematochezia
• most often found in cecum, terminal ileum, and ascending colon
• more common in older pts, confirm with angiography

Question 13

causes of ileus

Answer 13

• abdominal surgery, opiates, hypokalemia, and sepsis

Question 14

adenomatous polyps

Answer 14

• villous histology more associated with malignancy (tubular less likely to transition)
• can be asymptomatic, lower GI bleed, partial obstruction, secretory diarrhea (mucus secretion)

Question 15

hyperplastic polyps

Answer 15

• most common non-neoplastic polyp in the colon (> 50% found in rectosigmoid)

Question 16

juvenile polyps

Answer 16

• mostly sporadic lesion in children < 5
• if single, no malignant potential
• juvenile polyposis syndrome - multiple juvenile polyps in the Gi tract, increased risk of adenocarcinoma

Question 17

hamartomatous polyps

Answer 17

Peutz-Jeghers syndrome

• AD syndrome featuring multiple nonmalignant hamartomas throughout the GI tract, along with hyperpigmented mouth, lips, hands and genitalia
• associated with increased risk of CRC and other visceral malignancies

Question 18

reye syndrome

Answer 18

hepatoencephalopathy resulting in mitochondrial abnormalities, microvesicular fatt change, hypoglycemia, vomiting, hepatomegaly and coma
- aspirin metabolites decrease b-oxidation by reversible inhibition of mitochondrial enzyme

Question 19

alcoholic hepatitis

Answer 19

• swollen and necrotic hepatocytes with neutrophilic infiltration
• mallory bodes (intracytoplasmic eosinophilic inclusions) are present

Question 20

hepatic encephalopathy

Answer 20

• can be due to decreased NH3 removal (renal failure, diuretics, post-TIPS) or increased production (dietary protein, GI bleed, constipation, infection)
• treat with lactulose, low-protein diet and rifaximin
• alpha ketoglutarate is deficient in the brain

Question 21

viral hepatitis

Answer 21

• panlobular lymphocytic infiltrates, ballooning hepatocytes, hepatocyte necrosis/apoptosis
• round acidophilic Councilman bodies/apoptotic bodies

Question 22

cavernous hemangioma

Answer 22

• most common benign liver tumor, typically at 30-50 years
• biopsy contraindicated because of risk of hemorrhage, but would show cavernous blood filed spaces with single layer of epithelium

Question 23

hepatic adenoma

Answer 23

• rare, benign liver tumor, often related to OCPs or anabolic steroid use
• may regress spontaneously or rupture (abdominal pain and shock)

Question 24

angiosarcoma

Answer 24

• malignant tumor of endothelial origin, associated with exposure to arsenic, vinyl chloride
• express CD31 (PECAM)

Question 25

nutmeg liver

Answer 25

due to backup of blood in the liver (Budd Chiari or right sided heart failure)

Question 26

Budd-Chiari syndrome

Answer 26

occlusion of the IVC or hepatic veins with centrilobular congestion and necrosis, leading to congestive liver disease (hepatomegaly, ascites, abd pain and liver failure) - may develop varices and have visible abdominal and back veins - absence of JVD - associated with hypercoaguble states, polycythemia vera, pregnancy, HCC

Question 27

Gilbert syndrome

Answer 27

- mildly decreased UDP glucuronosyltransferase conjugation activity leads to decreased bili uptae by hepatocytes - asymptomatic or mild jaundice - elevated unconjugated bilirubin without overt hemolysis - bili will increase with fasting or stress

Question 28

Crigler-Najar syndrome, type I

Answer 28

- absent UDP-glucuronosyltransferase - presents in early life, pts die within a few years - jaundice, kernicterus, increased unconjugated bili - treat with plasmapheresis and phototherapy - type II is less severe and responds to phenobarb, which increases liver enzyme synthesis

Question 29

Dubin-Johnson syndrome

Answer 29

- conjugated hyperbilirubinemia due to defective liver excretion - grossly black liver, benign - high urinary corproporphyrin I levels

Question 30

rotor syndrome

Answer 30

- even milder than Dubin-Johnson and does not have a black liver

Question 31

Wilson disease

Answer 31

- inadequate hepatic Copper excretion (by hepatocute copper transporting ATPase ATP7B gene) and failure of copper to enter circulation and cerulosplasmin - copper accumulates int eh liver, brain, cornea, kidneys and joints - treat with penicillamine or trientine - AR inheritance - decreased ceruloplasmin, cirrhosis, corneal deposits, HCC, hemolytic anemia, basal ganglia degeneration, asterixis, dementia, dyskinesia, dysarthria

Question 32

hemochromatosis

Answer 32

- C282Y or H63D mutations in the HFE protein (increased endocytosis of the transferrin receptor) - fe absorption increased by 2 mech: increased DMT-1 expression on luminal side, decreased hepcidin synthesis by liver leads to increased ferroportin on basolateral surface - associated with HLA A3 - deposition of hemosiderin --> cirrhosis, diabetes and skin pigmentation - results in CHF, testicular atrphy, and increase risk of HCC - increased ferritin, increased iron, decreased TIBC, increased transferrin saturation

Question 33

primary biliary cirrhosis

Answer 33

- autoimmune reaction --> lymphocytic infiltrate and granulomas --> destruction of intralobular bile ducts - increased serum mitochondrial Abs, associated with other AI conditions (CREST, Sjogren, RA, celiac) - middle aged women with insidious onset - same mech as graft v. host disease

Question 34

primary sclerosing cholangitis

Answer 34

- unknown cause of concentric "onion skin" bile duct fibrosis --> alternating strictrures and dilation with "beading" of intra and extraheptaic bile ducts on ERCP - findings: hypergammaglobulinemia (IgM), associated with UC, can lead to secondary biliary cirrhosis and cholangiocarcinoma

Question 35

black stones

Answer 35

due to hemolysis

Question 36

brown stones

Answer 36

due to biliary infection | - releases b-glucuronidase into biliary tract by hepatocytes + bacteria

Question 37

causes of acute pancreatitis

Answer 37

GET SMASHED | - gallstones, ethanol, trauma, steroids, mumps, AI disease, scorpion sting, hypercalcemia/lipidemia, ERCP, drugs (sulfa)

Question 38

pancreatic pseudocyst

Answer 38

- lined by granulation tissue, not by epithelium, can rupture and hemorrhage

Question 39

Trousseau syndrome

Answer 39

- migratory thrombophlebitis - redness and tenderness on palpation of extremities - sign of pancreatic cancer

Question 40

Courvoisier sign

Answer 40

- obstructive jaundice with palpable, non-tender gallbladder | - sign of pancreatic cancer