Medical brain notes 15

  GALLSTONES (CHOLELITHIASIS)   Gallstones are frequently asymptomatic but can cause biliary colic (right upper quadrant pain due to impacted stones). Diagnosis is by U/S; the majority of stones are not radiopaque. Complications include cholecystitis, choledocholithiasis (calculi within the biliary tract), biliary tract obstruction, pancreatitis, and cholangitis.   Cholesterol stones  are composed mostly of cholesterol monohydrate. The incidence   increases with age. Risk factors include female gender, obesity, pregnancy, oral con-traceptives, and hormone replacement therapy. Native American Pima and Navajo Indians have an increased incidence of cholesterol gallstones.   Pigmented bilirubinate stones  are composed of calcium salts and unconjugated   bilirubin. Risk factors are chronic hemolytic anemias, cirrhosis, bacterial infection, and parasites ( Ascaris  or  Clonorchis  [ Opisthorchis ]  sinensis ).

  INFLAMMATORY CONDITIONS   Acute cholecystitis  is an acute inflammation of the gallbladder, usually caused by cys-tic duct obstruction by gallstones. It can present with biliary colic, right upper quad-rant tenderness on palpation, nausea and vomiting, low-grade fever, and leukocytosis. Complications include gangrene of the gallbladder, perforation and peritonitis, fistula formation and gallstone ileus (small bowel obstruction by a large gallstone). Acute acalculous cholecystitis is associated with surgery, trauma, and sepsis.   Chronic cholecystitis  is ongoing chronic inflammation of the gallbladder, usually   caused by gallstones. Well-developed examples show stromal and mural lympho-cytic and plasmacytic infiltrates. Macrophages and granulomas may also be present. The wall is thickened. Ascending cholangitis  is a bacterial infection of the bile ducts ascending up to the   liver, usually associated with obstruction of bile flow oftentimes fr...

  MISCELLANEOUS CONDITIONS   Cholesterolosis  refers to an accumulation of cholesterol-laden macrophages within   the mucosa of the gallbladder wall. Gross examination shows yellow speckling of the red-tan mucosa (“strawberry gallbladder”). Microscopic examination shows lipid-laden macrophages within the lamina propria.   Hydrops of the gallbladder  (mucocele) occurs when chronic obstruction of the cystic   duct leads to the resorption of the normal gallbladder contents and enlargement of the gallbladder by the production of large amounts of clear fluid (hydrops) or mucous secretions (mucocele).

  BILIARY TRACT CANCER   Gallbladder cancer  is frequently asymptomatic until late in the course. When the   tumor does present, it may be with cholecystitis, enlarged palpable gallbladder, or biliary tract obstruction (uncommon). X-ray may show a calcified “porcelain gallbladder.” Microscopically, the tissues show adenocarcinoma. The prognosis for gallbladder cancer is poor; 5-year survival rate is ~12%.   Bile duct cancer.  Bile duct carcinoma is carcinoma of the   extrahepatic   bile ducts,   while cholangiocarcinoma is carcinoma of the  intrahepatic  bile ducts. Klatskin tumor is a carcinoma of the bifurcation of the right and left hepatic bile ducts. Risk factors for bile duct cancer include  Clonorchis (Opisthorchis) sinensis  (liver fluke) in Asia and primary sclerosing cholangitis. Bile duct cancer typically presents with biliary tract obstruction. Microscopic examination shows adenocarcinoma arising from the bile ...