Pathology - gi Flashcards
Salivary gland tumors
adenoma - painless, mobile, recurs easily
carcinoma - malingant! mucinous and squamous
Warthin - benign, cystic, germinal centers
Achlasia cause
loss of myenteric plexus –> failure of relaxation of LES
progressive obstruction to solids AND liquids
incr. risk of esophageal SCC
may arise due to Chagas or malignancies
Boerhaave vs. Mallory-Weiss
transmural (leads to pneumomediastinum) vs. mucosal laceration
Esophageal strictures association
lye ingestion, acid reflux
Immunocompromised esophageal lesions
Candida: white pseudomembrane
HSV-1: punched-out ulcers
CMV: linear ulcers
Plummer-Vinson syndrome triad
Dysphagia, Iron deficiency anemia, Esophageal web
Barrett esophagus metaplasia
replacement of non-keratinized stratified squamous epithelium with non-ciliated columnar with goblet cells
Esophageal adenocarcinoma vs. SCC
adenocarcinoma: more common in US, fat, GERD
SCC: more common worldwide, alcohol, diverticula, esophageal web, hot liquids
Causes of acute gastritis
NSAIDs
Burns: decr. plasma volume leads to decr. mucosal barrier
Brain injury: incr. vagal stimulation, incr. Ach, incr. acid production
Type A chronic gastritis
Autoimmune disorder characterized by autoantibodies to parietal cells in the fundus/body
Type B chronic gastritis
caused by h. pylori bacteria
Menetrier disease
gastric hyperplasia leads to rugae hypertrophy, excess mucus production and decr. acid production
PRECANCEROUS
Gastric cancer associations
Acanthosis nigricans early local spread (liver mets) lesser curvature (intestinal) signet ring cells, mucin filled (diffuse cancer) linitis plastica (diffuse cancer)
Virchow node
Krukenberg tumor
Sister Mary Joseph nodule
increased gastric acid secretion leads to…
Duodenal ulcers (not gastric!)
Location of hemorrhage in ulcers
gastric ulcer on lesser curvature = left gastric artery
duodenal ulcer on posterior wall = gastroduodenal artery
Duodenal ulcer perforation
free air under diaphragm
referred pain to shoulder via phrenic nerve
Celiac disease associations
HLA-DQ2/DQ8
decreased bone density, dermatitis herpetiformis (papulovesicular skin rash, IgA deposits)
incr. risk of T cell lymphoma
marked atrophy of intestinal villi
Vitamins lost with pancreatic insufficiency
Malabsorption of A, D, E, K and B12
test with d-xylose absorption test: normal urinary excretion w/ pancreatic insufficiency, decreased excretion with intestinal mucosa defect (decr. glucose absorption)
Tropical sprue
Responds to antibiotics!
affects small bowel
Whipple disease
foamy/distended macrophages with PAS-positive granules in intestinal lamina propia
Also, cardiac symptoms, arthralgias, neurologic symptoms
most often in older men
Crohn’s gross morphology, micro, complications, extraintestinal, treatement
Skip lesions throughout GI tract, rectal sparing
Transmural inflammation, cobblestone mucosa, creeping fat, Noncaseating granulomas (Th1 mediated)
Strictures (leading to partial obstruction), fistulas
Migratory polyarthritis
Tx: steroids, azathioprine, antibiotics
Ulcerative colitis gross morphology, micro, complications, extraintestinal, treatement
Colonic only! Always with rectal involvement
Loss of haustra, only mucosal/submucosal
Crypt abscesses w/ neuts, Th2 mediated
assoc. PSC, toxic megacolon, colon cancer
Look for pyoderma gangrenosum
tx: 5-ASA (mesalamine), 6-MP
Causes for appendicitis in adults and children
Adults: fecalith
Children: lymphoid hyperplasia
False diverticula
only mucosa and submucosa outpouch
occur especially where vasa recta perforate muscularis externa
ex. Zencker diverticulum
Most common cause of LLQ pain
Diverticulitis
Histologic subtypes of colonic polyps
Hyperplastic - non-neoplastic, rectosigmoid area
Hamartomous - non-neoplastic, normal colonic tissue with distorted architecture
Adenomatous - neoplastic, chromosomal instability with APC/KRAS mutations, villous worse than tubular, >4cm = malignant, <1cm = benign
Serrated - premalignant, CpG hypermethylation with BRAF mutations, saw-tooth pattern of crypts
Polyposis syndromes
FAP - APC mutation (chromosomal instability), Ch. 5q, chromo
Gardner syndrome - FAP + bone tumors + hypertrophy of RPE + impacted teeth
Turcot syndrome - FAP + malignant CNS tumor
Peutz-Jeghers - hamartomas throughout GI tract + hyperpigmentation + incr. risk of cancer everywhere
Juvenile polyposis syndrome - hamartomas in children
Lynch syndrome
DNA mismatch repair defect leads to microsatellite instability
3 relatives w/ Lynch syndrome, 2 generations, 1 diagnosis before 50
Colon cancer locations
rectosigmoid > ascending > descending
Ascending (right) - exophytic mass, iron deficiency anemia, weight loss, more likely to bleed
Descending - infiltrating mass, partial obstruction, colicky pain, hematochezia, more likely to cause obstruction
Order of gene events in colon cancer
AK-53
Loss of APC (tumor supressor), gain of KRAS (protooncogene), loss of p53 (tumor suppressor)
Cirrhosis histology
diffuse bridging fibrosis
nodular regeneration via stellate cells
Ceruloplasmin
Copper-carrying protein
decr. in Wilson’s disease (copper accumulates in the liver and fails to be incorporated into ceruloplasmin during synthesis)
Reye syndrome
viral infection (VZV/influenza B) that is treated with aspirin (whose metabolites reversibly inhibit B-oxidation)
look for mitochondrial abnormalities, fatty liver, hypoglycemia, vomiting, hepatomegaly, coma
Progression of alcoholic liver disease
Hepatic steatosis –> alcoholic hepatitis –> alcoholic cirrhosis
Cirrhosis = hepatic/biliary injury + loss of function Prognosis = serum albumin levels, PT time
AST and ALT levels in alcoholic vs. fatty liver disease
AST > ALT: alcohol (ast = toast)
ALT > AST: fatty liver (L = lipids)
treatment for hepatic encephalopathy
lactulose
rifaximin - antibiotic
note: HE can be precipitated by blood/hemoglobin in the gut, which is converted into ammonia and absorbed into the bloodstream
Other liver tumors
cavernous hemangioma - most common, spongy and benign liver tumor, DON’T biopsy
hepatic adenoma - uncommon solitary mass, OCP or steroid use, may regress or rupture, look for sheet of cells
angiosarcoma - exposure to arsenic or vinyl chloride
mets from lung/breast
Budd-Chiari syndrome associations
hypercoagulable states, polycythemia, post-partum, HCC
thrombosis or congestion of the hepatic vein w/o JVD
alpha-1 antitrypsin deficiency
midfolded gene product aggregates in hepatocellular ER leading to cirrhosis
look for panacinar emphysema as well
Unconjugated vs. conjugated hyperbilirubinemia
Unconj: hemolytic, congenital, newborn, Crigler-Najjar, Gilbert
Conj: biliary tract obstruction, biliary tract disease, excretion defect, Dubin-Johnson, Rotor
Crigler-Najjar vs. Gilbert
absent UDP-glucoronosyltransferase vs. mildly decr.
incr. unconj bilirubin
CJ Type II is less severe and may be treated with phenobarbital (incr. liver enzyme synthesis)
Dubin-Johnson vs. Rotor
DJ: defective liver excretion of bilirubin glucoronides across canalicular membrane, grossly black liver
Rotor: milder, no black liver
Wilson’s associations
ATP7B gene
sx: hemolytic anemia, basal ganglia degeneration, asterixis, dementia, dyskinesia, dysarthria
tx: chelation w/ penicillinamine, trientine, oral zinc
Hemochromatosis triad
Cirrhosis + diabetes + skin pigmentation
look for heart failure and testicular atrophy
HFE gene mutation (HLA Class I like molecule) - overabsorption of iron in the gut and iron overload in tissues
women present later than men due to menstrual bleeding
Hemochromatosis labs
Incr. ferritin, iron
Decr. TIBC (transferrin is saturated)
HLA-A3
PBC vs. PSC histology
PBC: lymphocytic infiltrate and granulomas, destruction of intralobular ducts (middle-aged women, AMA)
PSC: onion skin bile duct fibrosis, alternating strictures and dilation, beading of intra/extrahepatic ducts on ERCP (young men with IBD, MPO, p-ANCA)
2 types of gallstones
Cholesterol (80%) - obesity, Crohn’s, decreased 7a-hydroxylase activity
Pigment
black: radiopaque, Ca, hemolysis
brown: radiolucent, infection
Activation of biliary colic
Neurohormonal eg. CCK secretion
Gallstone ileus
Fistula from gallbladder to small intestine leads to passage of stone into lumen, allowing for obstruction at the ileocecal valve
most common primary infection of gallbladder
CMV
Causes of acute pancreatitis
Gallstones, ethanol, trauma, steroids, mumps, autoimmune disease, scorpion sting, hyperTGs, ERCP, drugs (sulfa, NRTIs, protease inhibitors)
Look for calcifications! Fatty acids bind calcium salts
Pancreatic adenocarcinoma associations
disorganize glandular structure with cellular infiltration
CA 19-9 tumor marker
abdominal pain radiating to back
migratory thrombophlebitis (Trousseau syndrome)
obstructive jaundice with palpable, nontender gallbladder (Courvosier)
Carcinoid syndrome
if intestinal-limited: not many symptoms due to first-pass through liver. Symptoms arrive with mets to liver
enterochromaffin cells - APUD system (amine precursor uptake and decarboxylation)
Diffuse esophageal spasm
Periodic, non peristaltic contractions of the esophagus
Painful! Can clinically manifest with a chest pain similar to angina pectoris
Intermittent dysphagia and occasional chest pain
Acute hepatitis syndrome
All three have the same presentation: malaise, fever, skin rash, lymphadenopathy, then anorexia, RUQ pain, jaundice
Histology: panlobular lymphocytic infiltrates, ballooning hepatocytes, hepatocyte apoptosis/necrosis
Hep C is milder and can be asymptomatic
Hyperestrinism in cirrhosis
Decr. metabolism of ansdrostenedione –> incr. circulating estrogens
Also, incr. synthesis of SHBG –> incr. binding of testosterone
Results in gynecomastia, spider angiomata, testicular atrophy, decreased body hair
