gallbladder pathology Flashcards
What is biliary atresia? How does it present, and what are relevant complications?
failure to form the lumen of the extrahepatic biliary tree (bile ducts outside of the liver). leads to biliary obstruction within first 3 months. present with neonatal jaundice with conjugated bilirubin. it may progress to cirrhosis.
cholelithiasis causes:
solid round stones in the gallbladder d/t precipitation of cholesterol or bilirubin in bile. may be the result of supersaturation or decr. phospholipids like lecithin or bile acids that help dissolve bile (example: cholestyramine may reduce bile acids and cause stones), or stasis- incr. risk of bacterial growth, which can deconjugate bilirubin.
What is the most common type of gallstone? How do they appear on Xray? Risk factors?
cholesterol yellow stones. radiolucent, though a few may be calcified
What are risk factors for cholesterol stones?
age, Native American ancestry, obesity, rapid weight loss, cirrhosis, estrogen, Crohn disease, cystic fibrosis, clofibrate, multiparity.
Mechanisms:
1. cirrhosis: decr. bile salt production –> cholesterol precipitation
2. estrogen: incr. HMG CoA reductase –> incr. cholesterol synthesis; estrogen also incr. lipoprotein receptors on hepatocytes –> incr. cholesterol uptake
3. Crohn disease: often involves the terminal ileum, which is responsible for reabsorption of bile acids
4. clofibrate: lipid lowering drug that increases HMG CoA activity and decreases conversion of cholesterol to bile acids (also regulates PPAR to induce HDL synthesis and upregulates LPL to increase TG clearance).
bilirubin stones: x ray, gross, risk factors
radio-opaque, black stones. risks factors are extravascular hemolysis and biliary tract infection.
biliary tract infection, which can deconjugate the bilirubin.
seen in pts with chronic hemolysis, alcoholic cirrhosis, advanced age, and biliary infection.
What are the key complications that result from gallstones?
usually asymptomatic, but can cause biliary colic, acute or chronic cholecystitis, ascending cholangitis, gallstone ileus, or gallbladder carcinoma
biliary colic: presentation, potential outcomes
- biliary colic: waxing and waning RUQ pain due to the gallbladder contracting against a stone lodged in the cystic duct. this may lead to the stone being passed and symptom resolution, but could also get stuck in the common bile duct and cause acute pancreatitis or obstructive jaundice.
acute cholecystitis: definition and the underlying pathological process
acute inflammation of the gallbladder wall. impacted stone in the cystic duct results in dilation of the gall bladder with pressure ischemia, bacterial overgrowth, and inflammation.
How does acute cholescystis present?
RUQ pain that radiates to the right scapula. fever with elevated WBC count, nausea and vomiting, incr. serum alkaline phosphatase. risk of rupture if left untreated.
What is chronic cholecystitis? Defining features?
chronic inflammation of gallbladder due to chemical irritation from longstanding cholelithiasis, with or without superimposed bouts of acute cholecystitis.
causes hernation of gallbladder mucosa into the muscular wall (rokitansky-Aschoff sinus)
How does chronic cholecystitis present? complications?
vague RUQ pain, esp. after eating. may progress to porcelain gallbladder as a late complication.
What is the porcelain gallbladder?
hard, shrunken gallbladder d/t to chronic inflammation, fibrosis and dystrophic calcification. wall becomes calcified. it is a risk factor for gallbladder cancer
What is ascending cholangitis? How does it present?
bacterial infection of the bile ducts, usually due to ascending infection with enteric gram negative bacteria. presents with sepsis, jaundice, and abdominal pain. incr. incidence with choledocholithiasis (stone in biliary ducts. normally, bile helps wash away bacteria trying to get up to the gallbladder)
What is gallstone ileus?
stone enters and obstructs the small bowel. tdue to a fistula btw the gallbladder and the duodenum.
What is gallbladder carcinoma? where does it arise? risk factors? presentation?
adenocarcinoma arising from the glandular epithelium that lines the gallbladder wall. gallstones are a major risk factor, esp. with porcelain gallbladder. classically presents as cholecystitis in an elderly woman
