GI Diseases Flashcards
Primary Biliary Cirrhosis
Autoimmune destruction of intrahepatic bile ducts causing progressive liver failure
Presents with jaundice, pruritis, and hypercholesterolemia; primarily affects females
Alk phos and bilirubin are elevated; anti-mitochondrial antibody is present
Treatment: Liver transplant
Pleomorphic Adenoma
Most common salivary tumor (50%)
Benign, well-differentiated, slow growing tumor of the parotid gland; characterized by mixed cytology (epithelial cells in a chondromyxoid stroma)
Familial Adenomatous Polyposis (FAP)
Autosomal dominant mutation of APC gene (Wnt pathway)
Associated with development of pre-malignant polyps in the colon and non-pre-malignant polyps in the stomach; 100% progress to adenocarcinoma of the colon by age 30
Treatment is colectomy
Hereditary Hemochromatosis
Autosomal recessive disorder of the HFE gene resulting in unrestricted absorption of iron from the GI tract, which deposits in the liver, pancreas, heart, joints, and skin causing tissue damage and fibrosis.
Presents as cirrhosis, bronze pigmentation of the skin, diabetes, and cardiomyopathy
Pathology shows hemosiderin-laden hepatocytes
Treatment is therapeutic phlebotomy or chelation
Zollinger-Ellison Syndrome (ZES)
Hypergastrinemia and hypersecretion of gastric acid caused by gastrinoma; results in presence of peptic ulcers in non-traditional locations (distal duodenum, jejunum), esophagitis, and diarrhea
Ascending cholangitis
Bacterial infection of the common bile duct, usually caused by cholestasis in the setting of choledocholithiasis
Presents as Charcot’s triad: RUQ pain, jaundice, fever; can cause sepsis if untreated, presenting as Reynold’s Pentad (Charcot’s triad + confusion + hypotension)
Treated with IV antibiotics and endoscopic stone extraction by ERCP
Autoimmune Gastritis
Autoimmune destruction of gastric parietal cells due to presence of autoantibodies against proton pumps and IF
Associated with achlohydria and hypergastrinemia
Histology shows infiltration of lymphocytes and plasma cells into the gastric epithelium and lamina propria
Presents as pernicious anemia
Pernicious Anemia
Due to low B12 levels, often due to a problem with intrinsic factor production in the parietal cells of the gastric epithelium
Presents with low hemoglobin, low hematocrit, elevated MCV (>100), peripheral neuropathy
Celiac Sprue
Inflammatory disease of the small intestine caused by autoantibodies to gluten and gliadin peptides; associated with HLA-DQ2 and HLA-DQ8 as well as other autoimmune diseases (DM, thyroiditis) and dermatitis herpetiformis
Intestinal biopsy shows increased intraepithelial lymphocytes + villous blunting
Presents with diarrhea, steatorrhea, bloating, weight loss, abdominal pain, iron/folate malabsorption
Anti-tissue transglutaminase (tTg) IgA is elevated
Treatment: Lifelong gluten free diet
Irritable bowel syndrome
Functional gastrointestinal disorder characterized by abdominal pain and altered bowel habits in the absence of organic pathology
Presents as alternating diarrhea and constipation and chronic abdominal pain that improves with defecation
Indirect inguinal hernia
Passage of the peritoneum through the internal inguinal ring, into the scrotum; passes lateral to the inferior epigastric artery
Caused by failure of the processus vaginalis to close
Cushing’s ulcer
Acute stress ulcer associated with elevated intracranial pressure in trauma or severe illness; elevated ICP stimulates the vagus nucleus, causing increased acid secretion in the stomach, resulting in ulcer formation and bleeding
Achalasia
Degeneration of inhibitory interneurons in the myenteric plexus of the esophagus which are normally responsible for relaxation of the LES; causes abnormally high LES resting tone
Presents as solid/liquid dysphagia, weight loss, and non-sour regurgitation
Diagnosed by barium swallow or upper endoscopy revealing a dilated esophagus with “birds-beak” appearance; esophageal manometry shows lack of normal peristalsis and impaired post-deglutitive LES relaxation
Treated with dilation, Botox, or surgical myotomy; medications (CCBs, Nitroglycerine) are less effective
Diverticulosis
Outpouchings of the colon wall (mucosa and submucosa) through defects in the muscular layer (“false diverticulum”)
Risk factors: low fiber diet, chronic constipation, age
80% are benign/asymptomatic; risk of infection and rupture (acute diverticulitis)
May be asymptomatic or present as episodic painless rectal bleeding
Diverticulitis
Rupture of an infected diverticulum; may be uncomplicated, with minimal local abscess formation (treated by antibiotics) or complicated, with large abscess development or bowel obstruction (treated by percutaneous abscess drainage or surgery)
Risk of hemorrhage if mucosa erodes into penetrating vasa recta of the colon wall, presenting as heavy, painless hematochezia
Pseudomembranous Colitis
Usually caused by C. diff superinfection in the setting of recent antibiotic use (often 3rd generation Cephalosporins); toxins released cause disruption of epithelial cytoskeleton with tight junction barrier loss
Presets as fever, leukocytosis, abdominal pain, cramps, watery diarrhea
Presence of ‘pseudomembranes’ - an adherent layer of mucopurulent exudates (inflammatory cells + mucinous debris) at the sites of colonic epithelial injury
Barrett’s Esophagus
Squamous to columnar metaplasia of the distal esophageal epithelium caused by chronic inflammation in <10% of GERD cases
Carries the largest risk for esophageal adenocarcinoma
Biopsy shows Goblet cells
Treated with PPIs and monitoring for dysplasia
Esophageal Squamous Cell Carcinoma
Arises from the stratified squamous epithelium of the esophagus
Risk factors: Tobacco, alcohol, achalasia
Presents as progressive dysphagia and weight loss
Histology shows infiltrative, malignant glands
Esophageal adenocarcinoma
Arises from the distal esophagus in the setting of columnar metaplasia (Barrett’s esophagus)
Risk factors: Barrett’s esophagus, GERD, obesity, male gender, age
Presents as progressive dysphagia, weight loss, hematemesis
Gastroesophageal Reflux Disease (GERD)
Reflux of gastric contents into the esophagus due to transient and inappropriate LES relaxation
Risk factors: Tobacco, hiatal hernia, obesity
Presents as post-prandial heartburn, regurgitation, hypersalivation
Complications: Erosive esophagitis, Barrett’s esophagus, benign esophageal stricture
Treatment: PPIs, H2 blockers, antacids
Crigler-Najjar Syndrome
Congenital unconjugated hyperbilirubinemia caused by mutation in UDP-glucuronyltransferase (UGT1A1) which is responsible for conjugation of bilirubin in the liver
Leads to extremely high levels of unconjugated bilirubin in the serum
Complete lack of enzymatic function (Type I) is fatal without liver transplantation; reduced function of enzyme (Type II) causes jaundice but is otherwise asymptomatic
Gilbert Syndrome
Decreased activity of UDP-glucuronyltransferase (UGT1A1) causing mild, benign, fluctuating levels of unconjugated bilirubin
Relatively common; patients experience episodic jaundice, often during periods of physiologic stress
Dubin-Johnson Syndrome
Autosomal recessive conjugated hyperbilirubinemia; caused by hereditary defect in the transport of bilirubin glucuronides from hepatocytes into bile
Causes episodic jaundice
Pancreatic adenocarcinoma
Presents with jaundice, epigastric pain radiating to the back, and weight loss
Risk factors: Smoking, diabetes, chronic pancreatitis
Labs show elevated amylase, lipase, and alkaline phosphatase; tumor markers CA 19-9 and carcinoembryonic antigen (CAE) may be elevated
Primary Sclerosing Cholangitis
Idiopathic inflammatory disorder of the extra- and intra-hepatic biliary tree causing progressive fibrosis and stricture; leads to liver fibrosis and/or cirrhosis, associated with increased risk of cholangiocarcinoma
Presents as asymptomatic elevation of alkaline phosphatase progressing to fatigue, pruritis, and jaundice; primarily affects Caucasian males with ulcerative colitis
Labs show elevated alkaline phosphatase and bilirubin
Diagnosis is by cholangiography, which shows multiple biliary strictures alternating with areas of dilation (“string of pearl” appearance of bile duct)
Histology shows “onion-skin” fibrosis around bile duct
Treatment: Liver transplant is definitive treatment
Primarily affects Caucasian males 30-60; associated with ulcerative colitis
Carcinoid syndrome
Caused by metastasis of neuroendocrine cells of the GI tract to the liver; release of 5-HT into systemic circulation causes serotonin syndrome characterized by episodic flushing, diarrhea, wheezing, and right sided valvular heart disease
Hereditary Non-Polyposis Colorectal Cancer (HNPCC) / Lynch Syndrome
Autosomal dominant disorder associated with increased incidence of early onset colorectal cancer as well as extra-colonic cancer (endometrial, ovarian, urinary tract, small intestinal, gastric, biliary)
Caused by a mutation in DNA mismatch repair machinery leading to microsatellite instability
Small Bowel Obstruction
Presents with anorexia, vomiting, and abdominal pain; abdomen may be distended and diffusely tender
Upright X-ray shows dilated loops of small intestine with air-fluid levels
Usually caused by adhesion formation secondary to abdominal surgery; also caused by hernias and intraluminal tumors of the small intestine
Pompe’s Disease
Autosomal recessive glycogen storage disorder caused by deficiency in lysosomal a-1,4-glucosidase necessary for enzymatic degradation of glycogen; glycogen accumulates in the cytoplasm and the lysosomes
Associated with myopathies, especially cardiomyopathy and cardiac failure
Whipple’s Disease
Infection of the GI tract with gram-positive Tropheryma whippellii; macrophages engulf the organism and accumulate within the lamina propria and lymphatic tissue of the small intestine, causing lymphatic obstruction
Presents as a classic triad of diarrhea, weight loss, and malabsorption +/- arthritis, lymphadenopathy, and neurologic symptoms
Small intestinal biopsy shows villous blunting and infiltration of lamina propria with large macrophages filled with the organism
Trousseau syndrome
Venous thrombosis arising as a result of the hypercoagulable state associated with various cancers, especially pancreatic adenocarcinoma
Presents as the appearance and disappearance of venous thromboses throughout the body
Idiopathic intussusception
Characterized by telescoping of a proximal segment of bowel and attached mesentery into a distal segment; leads to lymphatic obstruction, swelling, and decreased perfusion of the affected bowel; unterated, venous and lymphatic congestion can cause intestinal edema, ischemia, perforation, and peritonitis
Presents as intermittent, colicky pain
GI manifestations of Scleroderma
Connective tissue proliferation with fibrosis of the gut wall, smooth muscle atrophy
Smooth muscle atrophy of the lower 2/3 of the esophagus can cause dysphagia secondary to weak peristalsis, and GERD progressing to esophagitis and/or stricture secondary to weakness of the LES
Gastric adenocarcinoma
May occur as either gland-forming (intestinal) type or, less commonly, as diffuse type (undifferentiated, associated with signet-ring cells and excess mucin production)
Risk factors: Chronic H. pylori infection, smoked foods, tobacco, male sex
Prognosis: Overall 5-year survival is 10% and related to depth of invasion
Treatment is endoscopic or surgical resection +/- adjuvant chemotherapy
Microscopic colitis
Chronic, mild, secretory diarrhea usually seen in older women; autoimmune etiology
Endoscopy is normal
Biopsy is diagnostic and shows either thickening of the basement membrane (collagenous colitis) or lymphocytic infiltration of mucosa without basement membrane thickening (lymphocytic colitis)
Necrotizing Enterocolitis
Occurs as a complication of prematurity; hypoxemia causes ischemic damage to the bowel wall leading to infection with possible perforation and peritonitis
Presents in the first 7-10 days of life as abdominal distension and bloody stools
Treatment: Bowel rest + antibiotics, possible surgical resection of the bowel
Perinatal Biliary Atresia
Etiology is unknown; characterized by a normal extrahepatic biliary tree at birth followed by progressive destruction
Presents as progressive jaundice and acholic stools 1-6 weeks after birth
Histology shows cholestasis within hepatocytes and bile ducts, reactive bile duct proliferation, variable inflammation and fibrosis
Treatment is hepatoportoenterostomy (Kasai procedure) by which the extrahepatic biliary system is excited and a loop of small bowel is connected to the hepatic hilum allowing for bile drainage
Patients often progress to cirrhosis and require liver cirrhosis
Embryonic / Fetal Biliary Atresia
Congenital structural anomaly of the biliary tree; usually associated with other congenital abnormalities
Presents as progressive jaundice (conjugated bilirubinemia) immediately after birth
Peutz-Jeghers polyps
Hamartomatous, pedunculated polyps occurring anywhere along the GI tract; polyps are benign but carry increased risk of pancreatic and breast cancer
Usually affects young adolescents
Associated with extra-GI manifestations, most commonly mucucutaneous pigmented lesions
Infantile Pyloric Stenosis
Hyperplasia of pyloric muscularis propria causing obstructive of gastric outflow
Presents in 2-3rd week of life with projectile vomiting and presence of firm abdominal mass
Treatemtn: Surgical myotomy of the pyloric muscularis
Allergic (eosinophilic) Esophagitis
Caused by an immune reaction against dietary antigens
Histology shows significant eosinophilic infiltrate of the epithelium, with variable submucosal fibrosis; these findings may affect the length of the entire esophagus uniformly
pH probe testing is normal; patients do not respond to acid blockade
Treat with elimination of the offending allergen from the diet +/- corticosteroids
Reflux esophagitis
Caused by inadequate gastroesophageal sphincter function; characterized by abnormal esophageal pH probe testing, usually affecting the distal esophagus
Histology shows mild intraepithelial infiltrate with eosinophils
Responds to acid blockade
Wilson’s Disease
Autosomal recessive disorder caused by defective synthesis of ceruloplasmin, which normally functions to chaperone copper to the liver for degradation and excretion in the bile; copper accumulates in liver and unbound copper released into circulation accumulates in the brain, kidneys, and corneas
Presents as Parkinsonism (2/2 deposits in the putamen), dementia (2/2 deposits in cortical neurons) and Kayser-Fleischer rings (2/2 deposits in cornea)
Treatment is plasmapheresis and chelation
Hemosiderosis
i.e. secondary hematochromatosis
Usually occurs following multiple blood transfusions
Presents similarly to hereditary hemochromatosis: cirrhosis + “bronze diabetes”
Liver biopsy shows iron deposits more prevalent in macrophages than in hepatocytes
Autoimmune hepatitis
Primarily affects females; presents as acute hepatitis flare followed by chronic hepatitis
Characterized by prominent plasma cells on histology with centrilobular necroinflammation
LFTs show increased AST and ALT with normal alkaline phosphatase; serology shows positive auto-antibodies and elevated IgG
Treated with steroids
Alpha-1-antitrypsin deficiency
Autosomal recessive mutation of alpha-1-antitrypsin protease inhibitor; patients with disease are most often homozygous for the Z allele
Most patients present with pulmonary emphysema; only 10% have liver disease
Histologically, abnormally folded A1A enzyme can be seen as intracytoplasmic accumulations of PAS-positive hyaline globules
Hepatocellular carcinoma
Most common primary malignant tumor of the liver; occurs almost exclusively in patients with risk factors: chronic alcohol abuse, hepatitis B or C, aflatoxin exposure
Cholangiocarcinoma
Invasive, gland-forming tumor of the bile ducts; may be intra- or extra-hepatic
Usually presents at an advanced stage with poor prognosis; primary risk factor is primary sclerosing cholangitis
Hepatic hemangioma
Most common primary hepatic tumor - incidence up to 2%, more common in females
Benign neoplasm of dilated vascular spaces
Presents as vague RUQ pain, early satiety, nausea, vomiting
Focal nodular hyperplasia (FNH)
Second most common primary hepatic mass; formed by hyperplastic parenchyma, commonly in association with hemangioma
Commonly diagnosed in 30s/40s, usually asymptomatic
Hepatocellular adenoma
Benign proliferation of hepatocytes appearing grossly as a well-circumscribed mass; mostly occurs in women of child-bearing age, associated with OC use
Mostly asymptomatic but can present with RUQ pain; risk of rupture into abdomen with hemorrhage
Acetaminophen-induced liver injury
Acetaminophen is a direct hepatotoxin
Causes coagulative necrosis beginning in zone 3 (centrilobular) and progressing to pan-lobular necrosis with high enough doses
Gardner’s Syndrome
Familial Adenomatous Polyposis (FAP) + Osteomas + Fibromatosis
Turcot’s Syndrome
Familial Adenomatous Polyposis (FAP) + CNS tumors (medulloblastoma)
Reye Syndrome
Rare, often fatal hepatoencephalopathy of childhood; associated with treatment of viral illnesses by aspirin
Mechanism: Aspirin metabolites transiently inhibit metabolism of fatty acids by hepatic mitochondria
Findings: Fatty liver, hepatomegaly, hypoglycemia, vomiting, coma
Tracheoesophageal fistula
85% occur where the upper esophagus ends in a blind pouch and the lower portion of the esophagus empties into the distal trachea
Complications: Polyhydramnios in utero, difficulty swallowing in the infant causing choking, aspiration, and filling of the stomach with air upon breathing
CXR shows large stomach air bubble
