Gastrointestinal Pathology

ravavoze's version from 2017-04-12 01:21

Grab bag

Question Answer
Pleomorphic adenomabenign mixed tumor
MC salivary gland tumor
Presentation of a pleomorphic adenomapainless, mobile mass that recurs frequently
Warthin's tumorPapillary cystadenoma lymphomatosum
benign cystic tumor with germinal centers
Mucoepidermoid carcinomaMC malignant tumor
mucinous and squamous components
Presentation: painful mass d/t common involvement of the facial nerve
Irritable bowel syndrome dxRecurrent abdominal pain with ≥ 2 of the following:
- pain improves with defecation
- change in stool frequency
- change in appearance of stool
AppendicitisAcute imflammation due to obstruction by fecalith (adults) or by lymphoid hyperplasia (kids)
True diverticulumall 3 gut wall layers outpouch (e.g. Meckel's)
False diverticulum(pseudodiverticulum)
only mucosa and submucosa outpouch
Occur esp where vasa recta perforate muscularis externa
DiverticulitisLLQ pain, fever, leukocytosis
May perforate → peritonitis, abscess formation, or bowel stenosis
sometimes called "left-sided appendicitis"
diverticulosismany false diverticula of the colon. Common cause of hematochezia
Colovesical fistulacolon-bladder fistula caused by diverticulitis
Causes pneumaturia
Zenker's diverticulumpharyngoesophageal false diverticulum.
Presenting symptoms of Zenker's diverticulumdysphagia, obstruction, foul breath
Meckel's diverticulumTrue diverticulum
Persistence of vitelline (omphalomesenteric) duct
Causes melena, RLQ pain, intussusception, volvulus, or obstruction near the terminal ilium
Dx: pertechnetate study for ectopic uptake
The 5 2's of...Meckel's diverticulum
2 inches long
2 feet from ileocecal valve
2% of population
Commonly presents in first 2 years of life
May have 2 types of epithelia - gastric/pancreatic
volvulustwisting of bowel around its mesentery
pathology of intussuceptiontelescopign proximal bowel into distal segment
presenting symptom of intussuceptioncurrent jelly stools



Question Answer
Achalasiafailure of relaxation of lower esophageal sphincter (LES) d/t loss of myenteric (auerbach's) plexus
High LES opening pressure and uncoordinated peristalsis → progressive dysphagia to solids and liquids
Achalasia dxBarium swallow shows dilated esophagus with an area of distal stenosis - "bird's beak"
Achalasia associations↑ risk of esophageal squamous cell carcinoma
2° achalasia may arise from Chagas' disease
Scleroderma (CREST syndrome) is assoc w esophageal dysmotility involving low pressure proximal to the LES
GERDHeartburn and regurgitation upon lying down w possible nocturnal cough and dyspnea - adult-onset asthma
Decrease in LES tone
Esophageal varicesPainless bleeding of dilated submucosal veins in lower 1/3rd of esophagus
2° to portal hypertension. MCC death in cirhosis
EsophagitisAssoc. w reflux, infxns, chemical ingestion
Bugs associated with esophagitisCandida, HSV-1 (punched out ulcers), CMV (linear ulcers)
Mallory-Weiss syndromeMucosal lacerations at the gastroesophageal junction
d/t severe vommiting
Leads to hematemesis
Usually alcoholics and bulimics
BoerHavve SyndromeTransmural esophageal rupture due to violent retching
Esophageal stricturesLye ingestion and acid reflux
Plummer-Vinson syndromeTriad:
- dysphagia (esophageal web)
- glossitis
- iron deficiency anemia

Remember Plumber's DIE
Barret's esophagusIntestinal (nonciliated columnar epithelium) replaces nonkeratinized (stratified) squamous epithelium in the distal esophagus
D/t chronic acid reflux (GERD)
Assoc w esophagitis, esophageal ulcers, esophageal adenocarcinoma
Typical presentation of esophageal cancerProgressive dysphagia (first solids, then liquids), weight loss, poor progonsis
Squamous cell - upper 2/3, keratin pearls
Adenocarcinoma - lower 1/3, metaplasia from Barrett's
Risk factors for esophageal adenocarcinomaBarret's, cigarettes, obesity, GERD
Risk factors for squamous cell carcinomaachalasia, alcohol, cigarettes, diverticula, esophageal web, hot liquids
most common esophageal cancer worldwidesquamous cell carcinoma
most common esophageal cancer in Americaadenocarcinoma
Adenocarcinoma what part of esophaguslower 1/3
Squamous cell carcinoma what part of esophagusupper 2/3
Achalasia on manometrypressure no longer 20mmHg now 60 because LES doesn't relax
scleroderma on manometryvery low LES pressure (0-10mmHg)
nutcracker esophaguspressure can go as high as 400mmHg

Malabsorption syndromes

Question Answer
Tropical sprueSimilar to celiac sprue, but it affects the entire small bowel
Whipple's diseaseInfection with Tropheryma whipplei (gram positive)
histology of Whipple's diseasePAS-positive foamy macrophages in intestinal lamina propria & mesenteric nodes
Symptoms of Whipple's diseaseStreatorrhea. Also Cardiac symptoms, Arthralgias and Neurologic symptoms. Most often in older men.
Celiac sprueAutoantibodies to gluten (gliadin) and anti-tissue transglutaminase
Distal duodenum and proximal jejunum
Histology shows loss of villi
Decreased IgA
Dermatitis Herpetiformis
Disaccharidase deficiencyOsmotic diarrhea
Follows injury - lactase is located at tips of intestinal villi
Histology of disacchardise deficiency (aka lactase deficiencynormal histology
Lactose intolerace testPositive for lactase deficiency if:
Administration of lactose produces symptoms AND serum glucose rises < 20 mg/dL
Abetalipoproteinemia↓ synthesis of apolipoprotein B → inability to generate chylomicrons → ↓ secretion of cholesterol/VLDL into bloodstream → fat accumulation in enterocytes
Early childhood with Vitamin E deficiency causing Ataxia (spinocerebellar degen.) and hemolytic anemia with thorny RBCs (acanthocytes)
Pancreatic insufficiencyD/t CF, obstructing cancer, and chronic pancreatitis
Malabsorption of fat and ADEK vitamins, not carbs normal D-xylose test
↑ neutral fat in stool
Celiac sprue associationsHLA-DQ2, HLA-DQ8
people of norther European descent
dermatitis herpetiformis (rash on extensor surface of forearm)
↑ risk of malignancy (T-cell lymphoma)
Celiac sprue findingsanti-endomysial, anti-tissue transglutaminase
anti-gliadin antibodies
blunting of villi
lymphocytes in the lamina propria
Screening: serum levels of tissue transglutaminase antibodies


Question Answer
Acute gastritisdisruption of mucosal barrier → inflammation
Caused by: stress, NSAIDs, alcohol, uremia
burns (Curling's ulcer - ↓ plasma volume → sloughing of gastric mucosa)
brain injury (Cushing's ulcer - ↑ vagal stimulation → ↑ ACh → ↑ H+ production)
Type A chronic gastritisAutoimmune disorder characterized by:
Autoantibodies to parietal cells
pernicious Anemia
Assoc w other Autoimmune disorders
Affects the fundus/Body
Type B chronic gastritisMC type
Caused by H. pylori infxn
↑ risk of MALT lymphoma
affects the Antrum
Menetrier's diseaseGastric hypertrophy with protein loss, parietal cell atrophy, and ↑ mucous cells
Rugae of stomach look like brain gyri b/c they're so hypertrophied
Intestinal stomach cancerAdenocarcinoma
Presents with acanthosis nigricans (hyperpigmented skin in body folds) either type cancer
Assoc w H. pylori, infxn, dietary nitrosamines (smoked foods), achlorhydria, chronic gastritis, and type A blood
Commonly on lesser curvature - looks like ulcer with raised margins
Diffuse stomach cancernot assoc w H. pylori
Signet ring cells
Stomach wall grossly thickened and leathery (linitis plastica)
Virchow's nodeinvolvement of left supraclavicular node by metastasis from stomach
Krukenberg's tumorbilateral stomach cancer mets to ovaries
Abundant mucus, signet ring cells
Sister Mary Joseph's nodulesubQ periumbilical metastasis of stomach cancer
Pain, Gastric vs Duodenal ulcerGastric: greater with meals - weight loss
Duodenal: Decreases with meals - weight gain
H. pylori infection, what could it be?Duodenal ulcer (100% have h. pylori), gastric ulcer (70%), type B chronic gastritis, or intestinal stomach cancer
Causes of gastric ulcer↓ mucolsal protection against gastric acid
Greater w meals
Causes of duodenal ulcer↓ mucosal protection or ↑ gastric acid secretion (Zollinger-Ellison syndrome). Decreases w meals
Risk of carcinoma in gastric vs. duodenal ulcerGastric: increased carcinoma risk
Duodenal: benign
Ulcer complications - Hemorrhagegastric ulcer on lesser curvature → bleeding from left gastric ulcer
Duodenal (posterior > anterior) - bleeding from gastroduodenal artery
Ulcer complications - PerforationDuodenal (anterior > posterior). May see free air under diaphragm referred pain to shoulder via phrenic nerve

Inflammatory bowel disease

Question Answer
DIsordered response to intestinal bacteriaCrohn's
Any portion of GI tractCrohn's
Discontinuous lesionsCrohn's
Spares the rectumCrohn's
Cobblestone mucosaCrohn's
Creeping fatCrohn's
"string sign" on barium swallow x-rayCrohn's
Linear ulcers, fissures, fistulasCrohn's
Noncaseating granulomasCrohn's
Lymphoid aggregates (Th1 mediated)Crohn's
Strictures, fistulas, perianal disease, malabsorption, nutritional depletionCrohn's
Diarrhea may or may not be bloodyCrohn's
Migratory polyarthritisCrohn's
Erythema nodosumCrohn's
Kidney stonesCrohn's
disrupts tight junctions between lumen of GI tract and rest of the bodyCrohn's
Ankylosing spondylitisboth
Tx of chron'sCorticosteroids, azathioprine, methotrexate, infliximab, adalimumab
Tx of ulcerative colitisASA preparations (sulfasalazine), 6-mercaptopurine, infliximab, colectomy
AutoimmuneUlcerative colitis
Continuous colonic lesionsUlcerative colitis
ALWAYS Rectal involvementUlcerative colitis
Mucosal and submucosal inflammation onlyUlcerative colitis
Friable mucosal pseudopolyps with freely hanging mesenteryUlcerative colitis
Loss of haustra → lead-pipe appearanceUlcerative colitis
Crypt abscesses and ulcersUlcerative colitis
No granulomas (Th2 mediated)Ulcerative colitis
Bloody diarrheaUlcerative colitis
MalnutritionUlcerative colitis
Sclerosing cholangitisUlcerative colitis
Toxic megacolonUlcerative colitis
greater risk of colorectal cancerUlcerative colitis
Pyoderma gangrenosumUlcerative colitis
1° sclerosing cholangitisUlcerative colitis


Question Answer
IntussusceptionTelescoping of 1 bowel segment into distal segment
Commonly at ileocecal jct
Symptoms of intussusception"currant jelly" stools and compromises blood supply
Mostly in kids - bull's eye appearance on X-RAY - it's an emergency in childhood
VolvulusTwisting of portion of bowel around its mesentery → obstruction and infarction
Cecum and sigmoid colon - where there is redundant mesentery
Usually in the elderly
Hirschsprung's diseaseFailure of neural crest cell migration → lack of ganglion cells/nerve plexuses in colon. associated w downs
presentation of hirschsprung'sbillious vomitting at birth
Duodenal atresiaEarly bilious vomiting with proximal stomach detention
Down syndrome
"Double bubble" on xray
Meconium ileusCF
Meconium plug obstructs intestine preventing stool passage at birth
Necrotizing enterocolitisNecrosis of intestinal mucosa and possible perforation
Colon is usually involved, but can involve entire GI tract.
Preemies are at risk d/t ↓ immunity
Ischemic colitisReduction in intestinal blood flow causes ischemia
Pain is out of proportion to physical findings - usually after eating → weight loss
Splenic flexure and distal colon
AdhesionFibrous band of scar tissue that forms after surgery ↠ small bowel obstruction
well-demarcated necrotic zones
AngiodysplasiaTortuous dilation of vessels → hematochezia
Cecum, terminal ileum, and ascending colon
Colonic polymps, tubular vs. villousTubular adenoma: smaller, rounded, more likely to be benign
Villous adenoma: long, finger-like projections. The more villous, the higher the risk of malignancy
Adenomatous polypprecacerous polyps
↑ malignant risk associated with ↑ size, villous histology, ↑ epithelial dysplasia
Hyperplastic polypMC non-neoplastic polyp in colon
Mostly rectosigmoid colon
serrated polypspremalignant via CPG hypermethylation
Peutz-Jeghers syndromeAD syndrome feat. multiple nonmalignant hamartomas throughout GI tract.
Also: hyperpigmented mouth, lips, hands, genitalia
↑ risk of CRC and other visceral malignancies
Familial adenomatous polyposisAD mutation of APC gene on chromosome 5q
2-hit hypothesis
100% progress to CRC
Thousands of polyps, pancolonic, always involves rectum
Gardner's syndromeFAP + osseous and soft tissue tumors
congenital hypertrophy of retinal pigment epithelium
Turcot's syndromeFAP + malignant CNS tumor (medulloblastoma)
Hereditary nonpolyposis colorectal cancer(Lynch syndrome)
AD mutation of DNA mismatch repair genes
~80% progress to CRC
proximal colon is always involved
Cancer locations in colonRectosigmoid > ascending > descending
Order of mutationsloss of APC gene puts colon at risk
K-RAS mutation takes it to adenoma stage
Loss of p53 takes it to carcinoma stage
Remember AK53
Carcinoid tumorSmall bowel neuroendocrine tumor (5-HT)
Wheezing, right-sided heart murmurs, diarrhea, flushing
Carcinoid syndrome is only symptomatic after it has spread outside the GI tract (usually to the liver) - b/c the liver metabolizes 5-HT
Tx: resection, octreotide, somatostatin
Right sided colon (ascending) cancers tend tobleed
Left sided colon (descending cancers tend toobstruct