title: Hepatobiliary pathology.
abstract: OBJECTIVE
  Studies are reviewed from the past year concerning the histopathology of liver and biliary diseases and their pathogenesis.
  
  
  RESULTS
  Several cases of acute hepatitis E showed portal and periportal hepatitis, with polarization of neutrophils to the interface region and lymphocytes more centrally in the portal tracts. Transfection of hepatitis C virus into cultured fetal hepatocytes resulted in sustained growth of 50-90 nm diameter viral particles. The ductular reaction in nonalcoholic steatohepatitis appears to evolve with fibrosis in response to hepatocyte replicative senescence. Hepatocellular release of hepcidin is critical for iron homeostasis in a manner analogous to pancreatic insulin for glucose homeostasis; this 'endocrine' focus was elaborated in an overview of hemochromatosis. Specific microscopic features of liver-cell adenomas combined with genetic analysis for hepatocyte nuclear factor 1alpha and beta-catenin mutations allows differentiation into four variants. Steroid-sensitive biliary strictures resembling primary sclerosing cholangitis but with increased serum immunoglobulin G4 and infiltrating immunoglobulin G4-positive plasma cells ('immunoglobulin associated cholangitis') are part of a spectrum of disorders including autoimmune pancreatitis and inflammatory pseudotumor.
  
  
  CONCLUSIONS
  Pathologic features of viral hepatitis C and E, immunohistochemistry for the ductular reaction and malignant liver tumors and several systemic disorders are among recent important pathology studies.
authors.affiliation: Department of Pathology, College of Physicians and Surgeons, Columbia University, New York, USA. jhl3@columbia.edu
authors.forename: Jay H
authors.initials: JH
authors.lastname: Lefkowitch
mesh_terms: D001659:Biliary Tract / Q000473:pathology*; D001661:Biliary Tract Neoplasms / Q000473:pathology; D002761:Cholangitis / Q000276:immunology / Q000473:pathology; D006801:Humans; D008099:Liver / Q000473:pathology*; D008107:Liver Diseases / Q000473:pathology* / Q000628:therapy; D016031:Liver Transplantation; D008264:Macrophages / Q000473:pathology