Histological assessment of cholestasis.

The microscopic identification of bile in sections of liver provides an important diagnostic challenge for the histopathologist, particularly in differentiating the many causes of intrahepatic cholestasis from mechanical bile duct obstruction. The pathologist's chief goal in evaluating the cholestatic liver is to distinguish intrahepatic cholestasis (seen in conditions such as drug hepatotoxicity, viral hepatitis, sepsis, or mutations affecting bile transporters) from large bile duct obstruction caused by conditions such as choledocholithiasis, pancreatic carcinoma, biliary stricture, or primary sclerosing cholangitis (PSC). This distinction carries major therapeutic and prognostic significance, because surgical, endoscopic,or radiologically guided intervention is likely to be undertaken if the pathologic features point to mechanical obstruction of the bile ducts. The histologic assessment of cholestasis, in broad terms, therefore, is a morphologic approach to distinguish between medical jaundice and surgical jaundice.