Chapter 18- The Liver Flashcards
What are the functions of the liver?
Glycogen storage
Toxin removal
Nutrient processing
Nutrient storage (Vit A and iron)
Cholesterol, albumin and clotting factor production
Alcohol and drug metabolism
Bile production
What is the function of bile?
Major excretory route for exogenous lipophilic substances and endogenous substrates not readily excreted by the kidney
Cholesterol elimination
Excretion of IgA, cytokines, stimulates innate immune system
Hormone and pheromone excretion
Bile salts emulsify dietary fats
What reversible changes can occur in the liver?
- Steatosis (fat accumulation)
2. Cholestasis (bilirubin build up)
How do liver scars form and regress?
Stellate cells are activated and converted to fibrogenic myofibroblasts (cytokines)
Conversion reversed if insult stops
Metalloproteinases from hepatocytes break down scar
What is associated with acute liver failure?
Encephalopathy
What is fulminant hepatic failure?
Encephalopathy within two weeks of jaundice
What are the characteristics of acute liver failure?
Massive hepatic necrosis
Small and shrunken liver
Nausea, vomiting and jaundice
Reduced clotting factors
Portal hypertension
What is responsible for about 50% of acute liver failure?
Acetaminophen
What is hepatorenal failure?
Form of renal failure in patients with liver failure
What are causes of chronic liver failure?
Alcohol abuse
Viral hepatitis
Nonalcoholic steatohepatitis
What is the morphology of cirrhosis?
Regenerative nodules surrounded by fibrous bands and degrees of vascular shunting
What are the characteristics of chronic liver failure?
Jaundice
Encephalopathy
Coagulopathy
Intense pruritis
Spider angiomas
Hyperestrogenemia
What causes death in chronic liver failure?
Hepatic encephalopathy
Bleeding from esophageal varices
Bacterial infections
Hepatocellular carcinoma
What is portal hypertension?
Increased flow and/or resistance to portal blood flow
What are the three types of portal hypertension and what can cause them?
- Prehepatic- obstructive thrombosis, portal vein narrowing and massive splenomegaly with increased splenic vein flow
- Intrahepatic- cirrhosis, schistomiasis, massive fatty change, granulomatous disease, nodular regenerative hyperplasia
- Posthepatic- RSHF, constrictive pericarditis or hepatic vein obstruction
What is acute on chronic liver failure?
Acute liver failure that has developed in patients with stable but advanced chronic liver disease
What are the different kinds of hepatitis and their characteristics?
Hep A- damage due to CD8 cells, fecal-oral
Hep B- acute and nonprogressive chronic hepatitis, acute hepatic failure, damage due to CD8 cells, vertical and horizontal transmission
Hep C- often progresses to chronic disease, horizontal transmission
Hep D- dependent on HBV infection (superinfection), progression to cirrhosis
Hep E- enterically transmitted, self limiting, fatal in pregnant women
What forms of hepatitis can increase hepatocellular carcinoma?
Hep B
Sometimes Hep D
What types of hepatitis have vaccines available?
Hep A and B
How can extrahepatic infections affect the liver?
Can induce hepatic inflammation
What is the morphology of parasitic infections in the liver?
Hepatic abscesses
What type of autoimmune hepatitis is autoimmune hepatitis?
Chronic and progressive
What is the most common hepatotoxic causing chronic liver disease?
Alcohol
What are the forms of alcohol induced liver injury and their characteristics?
- Hepatocellular steatosis or fatty change- accumulation of lipid droplets, greasy liver
- Alcoholic (steato-) hepatitis- foci of cells that undergo swelling and necrosis, clusters of inflammatory cells, Mallory-Denk bodies, neutrophilic reactions
- Steatofibrosis- activation of stellate cells and portal fibroblasts, perisinusoidal scar accumulated and spreads outwards, cirrhosis in late stages
What are Mallory-Denk bodies?
Clumped eosinophilic material in the liver
What is Laennec/micronodular cirrhosis?
End stage alcoholic liver disease
Where does fibrosis begin in steatofibrosis?
Central vein sclerosis
What are the different types of metabolic liver disease?
Nonalcoholic fatty liver disease (NAFLD)
Hemochromatosis
Wilson disease
Alpha-1-antitrypsin deficiency
What is NAFLD?
Hepatic steatosis in the absence of heavy alcohol consumption
What is NAFLD associated with?
Metabolic syndrome
NAFLD increases the risk of what?
HCC
What do the hepatocytes in NAFLD look like?
Filled with fat vacuoles
What is the major cause of mortality?
CVD
What is hemochromatosis?
Excessive iron accumulation in the parenchymal cells of various organs
What are the forms of hemochromatosis?
- Hereditary
2. Hemosiderosis
What can cause hemosiderosis?
Repetitive transfusions
Ineffective erythropoiesis
Increased iron intake
Chronic liver disease
How is hemochromatosis treated?
Regular phlebotomy
How is hemochromatosis visualized?
Prussian blue stain
What is Wilson disease?
Impaired copper excretion
How does Wilson disease affect the liver?
Minor to severe damage
Fatty change, acute and chronic hepatitis
What are Kayser-Fleischer rings?
Green/brown/copper deposits in Descemeh membrane of the cornea
What are the effects of alpha-1-antitrypsin deficiency?
Emphysema- no inhibition of proteases at inflammatory sites
Hepatic disease- accumulation of misfolded proteins (necrosis/apoptosis)
What stain is used to demonstrate alpha-1-antitrypsin deficiency?
PAS (positive)
What is caused by excess bilirubin?
Jaundice
Icterus
Kernicterus
What is cholestasis?
Impaired bile formation/flow leading to intrahepatic bile pigment in the parenchyma
What are the effects of cholestasis?
Jaundice
Pruritis
Skin xanthomas
Intestinal malabsorption
Bile canaliculi and hepatocyte degeneration
Feathery degeneration
What is large bile duct obstruction commonly due to?
Extrahepatic cholelothiasis
What can prolonged obstruction of the large bile duct cause?
Biliary cirrhosis
What can large bile duct obstruction promote?
Ascending cholangitis
How can large bile duct obstruction be corrected?
Surgically
Cholestasis of sepsis is due to what kind of infection?
Intrahepatic bacterial infection
What is the morphology of cholestasis of sepsis?
Large, dark, bile concentrations with dilated canals
What is primary hepatolithiasis?
Intrahepatic gallstone formation
Calcium bilirubinate stones in distended intrahepatic bile ducts
Ducts in primary hepatolithiasis show what?
Chronic inflammation
Mural fibrosis
Peri-biliary gland hyperplasia without obstruction
What is the liver parenchyma like in primary hepatolithiasis?
Destroyed by inflammation
What is neonatal cholestasis?
Prolonged conjugated hyperbilirubinemia
What is biliary atresia?
Obstruction of the extrahepatic biliary tree in the first three months of life
What are the two forms of biliary atresia and their characteristics?
- Fetal- associated with other abnormalities
2. Perinatal- biliary tree is destroyed after birth
What are the two forms of autoimmune cholangiopathies and their characteristics?
- Primary biliary cirrhosis- inflammatory destruction of intrahepatic bile ducts
- Primary sclerosing cholangitis- fibrosis of the extra and intrahepatic biliary tree
What can primary biliary cirrhosis progress to?
Cirrhosis
What characteristic radiologic feature is seen in primary sclerosing cholangitis?
Beading of contrast material
What are two types of structural anomalies of the biliary tree?
- Choledochal cysts
2. Fibropolycystic disease
Choledochal cysts can predispose the biliary tree to what pathology?
Stone formation
What effects can choledochal cysts cause?
Stenosis
Stricture
Pancreatitis
Obstructive biliary complications
What is fibropolycystic disease?
Group of lesions that cause congenital malformations of the biliary tree
What lesions are associated with fibropolycystic disease and what are their characteristics?
Von Meyenburg complexes- small bile duct hamartomas
Biliary cysts- intra or extrahepatic
Congenital hepatic fibrosis- collagenous tissue forms septae that divide the liver
What is Caroline syndrome?
Cystic dilation of biliary ducts with congenital hepatic fibrosis
Circulatory disorders affect what aspect of the liver?
Morphology
How are liver circulatory disorders grouped?
Inflow
Intrahepatic
Outflow
What are liver infarcts rare?
Dual blood supply
What can cause localized infarcts of the liver?
Thrombosis or compression of an intrahepatic artery branch
How does hepatic artery thrombosis differ in a transplanted liver?
Leads to infarction of major ducts (arterial supply only)
What is Budd-Chiari syndrome?
Thrombosis of major hepatic veins
How does shock affect the liver?
Hepatocyte necrosis around the central vein (centrilobular necrosis)
What is the morphology of passive liver congestion?
Nutmeg liver- centrilobular necrosis with hemorrhage
What are the symptoms of preeclampsia?
Hypertension
Proteinuria
Peripheral edema
Coagulation abnormalities
Why is eclampsia more severe than preeclampsia?
Neural manifestations are present (convulsions)
What is HELLP syndrome?
Fibrin deposits cause hemorrhage- coagulative necrosis, hepatic hematoma
Hemolysis
Increased liver enzymes
Decreased platelets
How can HELLP lead to eclampsia?
Hepatic rupture
What is nodular hyperplasia?
Benign nodule(s) in the absence of cirrhosis
What are the two forms of nodular hyperplasia and their characteristics?
- Focal- we’ll demarcated, poorly encapsulated with central grey-white stellate scar
- Regenerative- entire liver is transformed, looks cirrhotic
What are two forms of benign liver neoplasms?
- Cavernous hemangiomas
2. Hepatocellular adenomas
What are hepatocellular adenomas associated with?
Oral contraceptive use in young women
Most malignant tumours in the liver are primary or metastatic?
Metastatic
What is the most common original site of hepatic metastatic cancer?
Colon
What are the types of liver cancer and what are their characteristics?
- Hepatoblastoma- children
- Hepatocellular carcinoma (HCC)- emerges from chronic liver disease (HBV, toxic injury)
- Fibrolamellar carcinoma- HCC variant, single, scirrhotic mass
- Cholangiocarcinoma- arise from biliary tree
What are Klatskin tumours?
Prehilar cholangiocarcinomas
What is the most common cholangiocarcinoma?
Klatskin tumours
What is the morphology of intra and extrahepatic cholangiocarcinomas?
Intra- branching or solid masses
Extra- small lesions with wall thickening
What congenital anomalies are associated with the gallbladder?
Absent/ectopic
Bilobed
Phrygian cap (folded fundus)
Cysts
Biliary atresia
Adenomyomatosis- hyperplastic cholecystosis of the gallbladder wall
What is cholelothiasis and what causes it?
Gallstones
Supersaturation of cholesterol in bile
What can increase the risk of forming gallstones?
Mucous hypersecretion
Biliary colic
Gallbladder hypomotility
Empyema
Perforation
Fistulas
Cholangitis
Obstruction
Pancreatitis
What are the differences between pure and impure cholesterol stones?
Pure- pale yellow, round, granular, hard
Impure- grey-white/black, may be lamellated, more opaque
What are the differences between black and brown pigment stones?
Black- sterile, small, many, friable, radiopaque
Brown- infected, laminated, greasy, soft
What are the characteristics of acute cholecystitis?
Enlarged, tensed, bright red/blotchy or green-black gallbladder
Fibrinous exudate on serosa
Bile can be turbid with pus and fibrin and blood
Where is a stone often found in acute cholecystitis?
Neck of the gallbladder
What are the different forms of acute cholecystitis?
Calculous
Acalculous (ischemia)
Empyema (pus filled)
Gangrenous
Emphysematous (gas forming bugs, bubbles in wall)
What are the characteristics of chronic cholecystitis?
Most have stones (bile supersaturation)
Variable size
Thickened wall, preserves mucosa
Cholesterolosis
Rokitansky-Aschoff sinuses- mucosa outpouchings
Porcelain gallbladder- wall calcification
Xanthogranulomatous cholescystitis- massive wall thickening with nodular gallbladder
What is the most common extrahepatic biliary tract malignancy?
Gallbladder cancer
What are the two patterns of gallbladder cancer?
- Infiltrating
2. Exophytic
What is a risk factor for developing gallbladder cancer?
Chronic inflammation
Most gallbladder cancers have what?
Gallstones