USMLE Step 2 (Fach) / Gastroenterology (Lektion)

Step 2 CK

Diese Lektion wurde von estoffel erstellt.

Lektion lernen

zurück  |  weiter 1 / 3

• Colorectal cancer Third leading cause of cancer-related deaths in the US overall. Predisposing factors:- Colorectal adenomas- Family history- Hereditary syndromes: Familial adenomatous polyposis, hereditary nonpolyposis ...
• Angiodysplasia Tortuous, dilated veins in submucosa of the colon (usually proximal) wall.- Associated with advanced age (> 60 years), end-stage renal disease, von Willebrand disease, and aortic stenosis Clinical features:- ...
• Acute mesenteric ischemia Epidemiology:- Mainly occurs in adults > 60 years- Young people with A-fib, vasculitis, or hypercoagulable states can also be affected Etiology:- Acute arterial embolism (∼ 50% of cases): generally ...
• Chronic mesenteric ischemia Epidemiology:- Generally occurs in adults > 60 years Clinical features:- So-called 'abdominal/intestinal angina'→ Recurrent, dull, postprandial epigastric pain usually within the first hour after eating→ ...
• Ogilvie's syndrome (Acute megacolon) Acute dilation of the colon in the absence of a mechanical obstruction, characteristically seen in severely ill or postoperative patients. Etiology:- Recent major surgery or trauma- Serious medical illnesses ...
• Volvulus Twisting of a loop of bowel on its mesentery. Epidemiology:- Volvulus: 3rd most common cause (∼ 10-15%) of intestinal obstruction in the United States→ Sigmoid volvulus (most common, 80%)→ Cecal ...
• Cirrhosis Etiology:- Long-standing alcohol abuse (one of the two most common causes of chronic liver disease in the USA)- Viral hepatitis B, C, and D - Autoimmune: Primary biliary cirrhosis, primary sclerosing ...
• Esophageal variceal hemorrhage Esophageal variceal hemorrhage refers to the bleeding of dilated sub-mucosal veins (varices) of the distal esophagus and is a dangerous consequence of portal hypertension. It is the most common form of ...
• Spontaneous bacterial peritonitis Bacterial infection of ascitic fluid in the absence of other intra-abdominal causes Etiology:- Patients with progressed liver cirrhosis or patients receiving peritoneal dialysis. - Bacterial species: ...
• Wilson's disease Wilson disease (hepatolenticular degeneration) is an autosomal recessive metabolic disorder in which impaired copper excretion causes copper to accumulate in the body. Age of onset: 5-35 years  Pathophysiology: ...
• Hemochromatosis Primary hemochromatosis:- Homozygous or heterozygous for the HFE gene defect (chromosome 6)- Most commonly affects C282Y and H63- Defective binding of transferrin to its receptor → liver stops producing ...
• Hepatic adenoma - Most often seen in young women (15 to 40 years of age) Etiology:- Oral contraceptive use- Anabolic steroid use Clinical features:- Usually asymptomatic- Large tumors → upper abdominal pain, fullness, ...
• Cavernous hemangioma Most common type of benign liver tumor. Etiology:- Estrogen therapy associated with increased growth in size Clinical findings- Usually asymptomatic- Large tumors → upper abdominal pain, fullness, and ...
• Focal nodular hyperplasia Benign liver tumor without malignant potential. - Occurs in women of reproductive age. - There is no association with oral contraceptives. Clinical features:- Usually asymptomatic- Hepatomegaly may be ...
• Hepatocellular carcinoma Epidemiology:- Highest incidence in Southeast Asia and Africa- Peak incidence in the US: 70-75 years Etiology:- Liver cirrhosis (80% of cases)- Risk factors independent of cirrhosis→ Chronic hepatitis ...
• Budd-Chiari syndrome Etiology:- Secondary to conditions associated with hypercoagulability (most common)→ Polycythemia vera (most important cause) → Paraneoplastic thrombocytosis→ Pregnancy→ Clotting disorders (e.g., ...
• Liver function tests - Aminotransferases - ALT is more sensitive and specific than AST for liver damage.- ALT and AST usually have a similar increase. The exception is in alcoholic hepatitis, in which the AST–ALT ratio may be >2:1. - If ...
• Liver function tests - Alkaline phosphatase Not specific to liver—also found in bone, gut, and placenta. - ALK-P is elevated when there is obstruction to bile flow (e.g., cholestasis) in any part of the biliary tree. Normal levels make cholestasis ...
• Cholelithiasis Epidemiology:- Sex: F > M (2-3:1)- Prevalence: approx. 10-20% of the adult population in the United States- Peak incidence: > 40 years Risk factors:- Obesity- Female sex, especially among those receiving ...
• Cholecystitis Etiology:- Due to obstructing cholelithiasis: 90% of cases, with secondary bacterial infection (E. coli, Klebsiella, Enterobacter) Clinical features:- RUQ pain→ More severe and prolonged (> 6 hours) ...
• Acalculous cholecystitis Acute cholecystitis without stones obstructing the cystic duct (up to 10% of patients with acute cholecystitis), usually seen in critically ill patients. It usually presents with secondary infection. ...
• Choledocholithiasis Etiology:- Cystic fibrosis- Prolonged total parenteral nutrition - History of cholelithiasis, though patients remain at risk of choledocholithiasis postcholecystectomy Clinical features:- Colicky RUQ/epigastric ...
• Cholangitis Etiology:- Obstruction of biliary tracts (e.g., caused by biliary lithiasis, stenosis, or malignancy), with secondary bacterial infection- May follow cholecystitis- Ascending infection most commonly from ...
• Primary sclerosing cholangitis Primary sclerosing cholangitis (PSC) is a progressive chronic inflammation of both the intrahepatic and extrahepatic bile ducts.  Epidemiology:- Sex: M > F (2:1)- Age: The median age at diagnosis is ...
• Primary biliary cirrhosis Epidemiology:- Sex: F > M (∼ 9:1)- Age range: 30-65 years- Most common cause of vanishing bile duct syndrome Clinical features:- Fatigue (usually the first symptom)- Marked generalized pruritus- Hepatomegaly, ...
• Cholangiocarcinoma Risk factors:- Primary sclerosing cholangitis (most common risk factor)- Liver fluke infection (e.g., Clonorchis sinensis, Opisthorchis viverrini)- Choledocholithiasis- Chronic viral hepatitis (e.g., ...
• Choledochal cysts Cystic dilatations of biliary tree involving either the extrahepatic or intrahepatic ducts, or both. - More common in women (4:1) Clinical features: epigastric pain, jaundice, fever, and RUQ mass Complications: ...
• Bile duct stricture Etiology:- Iatrogenic injury (e.g., prior biliary surgery such as cholecystectomy, liver transplantation)- Recurring choledocholithiasis- Chronic pancreatitis- PSC Clinical features: those of obstructive ...
• Appendicitis - Lifetime risk: ∼ 8%- Peak incidence: 10-19 years of age Etiology: Obstruction of appendiceal lumen by- Lymphoid tissue hyperplasia- Fecalith- Less common: foreign bodies, worm infestations, intestinal ...
• Acute pancreatitis Etiology:- Biliary pancreatitis (e.g., gallstones, constriction of the ampulla of Vater) ∼ 40% of cases- Alcohol-induced (∼ 30% of cases)- Idiopathic (∼ 15%–25% of cases)- Hypertriglyceridemia, ...
• Pancreatitis - Complications 1. Pancreatic necrosis (may be sterile or infected)- Sterile pancreatic necrosis – infection may develop, but half of all cases resolve spontaneously. These patients should be monitored closely in ...
• Chronic pancreatitis Etiology:- Alcohol abuse (60-70% of cases, esp. men)- Pancreatic ductal obstruction (< 10%): strictures (e.g., due to trauma, stones)- Tobacco use- Idiopathic pancreatitis (20-30%)- Hereditary pancreatitis ...
• Pancreatic cancer Epidemiology:- Sex: M > F- Age of onset: 60-80 years- More common in African Americans Risk factors:- Smoking- Chronic pancreatitis- High alcohol consumption- Type 2 diabetes- Obesity- Exposure to chemicals ...
• Gastrointestinal bleeding Upper gastrointestinal bleeding (70-80%): The source is located proximal to the ligament of Treitz. Lower gastrointestinal bleeding (20-30%): The source is located distal to the ligament of Treitz (usually ...
• Esophageal cancer Risk factors:Adenocarcinoma- Gastroesophageal reflux: Barrett's esophagus- Obesity- Smoking- Achalasia- Localization: mostly in the lower ⅓ of the esophagusSquamous cell carcinoma (SCC)- Alcohol consumption- ...
• Achalasia Etiology:- Primary achalasia (most common): cause is unknown- Secondary achalasia (pseudoachalasia): The presentation and manometric findings of a mechanical cause of obstruction (e.g., a malignancy) ...
• Diffuse esophageal spasms Clinical features:- Dysphagia- Retrosternal chest pain: Squeezing type, occurs with eating- Regurgitation Diagnostics:1. Rule out MI with ECG and troponins2. Manometry→ Simultaneous multi-peak contractions→ ...
• Esophageal hiatal hernias Etiology:- Lax diaphragmatic esophageal hiatus: Advanced age, smoking, obesity, genetic predisposition (rare)- Prolonged periods of increased intra-abdominal pressure: Pregnancy, ascites, chronic cough, ...
• Mallory-Weiss syndrome Longitudinal mucous membrane tears (limited to the mucosa and submucosa) at the gastroesophageal junction. Precipitating factors:- Severe vomiting- Blunt abdominal trauma- Strained defecationPredisposing ...
• Plummer-Vinson syndrome Triad of:1. Upper esophageal webs 2. Dysphagia3. Iron deficiency anemiaOther: Koilonychia (spoon-shaped fingernails), atrophic oral mucosa 10% of patients develop SCC of the oral cavity, hypopharynx, ...
• Schatzki ring A circumferential ring in the lower esophagus that is always accompanied by a sliding hiatal hernia. Etiology:- Ingestion of alkali, acids, bleach, or detergents (e.g., in suicide attempts). Clinical ...
• Esophageal diverticula Localization:- Upper esophageal diverticulum→ Pharyngoesophageal diverticulum→ Most common type: Zenker's diverticulum at Killian's triangle- Middle esophageal diverticulum: diverticulum at the tracheal ...
• Peptic ulcer disease Etiology:- H. pylori→ Duodenal ulcers: up to 90% are due to H. pylori infection→ Gastric ulcers: up to 80% are due to H. pylori infection- Chronic gastritis of other etiology - Long-term use of NSAIDs, glucocorticoids- ...
• Gastroesophageal reflux disease Risk factors/associations:- Lifestyle habits such as smoking, caffeine and alcohol consumption- Stress - Obesity - Pregnancy- Diaphragm dysfunction- Angle of His enlargement (> 60°) - Iatrogenic (e.g., ...
• Acute gastritis Etiology:- NSAIDs/aspirin- H. pylori infection- Alcohol, smoking, caffeine- Extreme physiologic stress (e.g., shock, sepsis, burns) Clinical features:- Hematemesis (coffee-ground appearance or bright ...
• Chronic gastritis Etiology:- H. pylori infection (> 80% of cases)- Autoimmune gastritis Clinical features:- Mostly asymptomatic- Epigastric pain- Dyspepsia- Nausea and vomiting Diagnostics:- Esophagogastroduodenoscopy ...
• Gastric cancer Epidemiology:- Peak incidence: 70 years- High incidence in South Korea and Japan Etiology:- Atrophic gastritis- H. pylori infection: ↑ risk of intestinal gastric cancer but not with diffuse gastric ...
• Gastric MALToma - Peak incidence: 7th and 8th decades Etiology:- Association with H. pylori Clinical features:- Present similarly to peptic ulcer disease and gastritis- Abdominal pain- Melena, hematemesis, potentially ...
• Small bowel obstruction Etiology:- Adhesions (e.g., postoperative, prior abdominal surgery)- Incarcerated hernia- Malignant tumors or metastases- Strictures (e.g., Crohn's disease, congenital, radiation enteritis)- Foreign body- ...
• Paralytic ileus Etiology:- Intra-abdominal surgery or trauma (e.g., laparotomy, retroperitoneal hemorrhage)- Medication (e.g., anticholinergics, opioids, antidepressants)- Electrolyte disturbances (e.g., hypokalemia)- ...

zurück  |  weiter 1 / 3