Liver biopsy assessment in chronic hepatitis.

Liver biopsy has been a major diagnostic tool in the evaluation of individuals with chronic hepatitis for many decades and remains the most direct way of visualizing hepatic necroinflammation and fibrosis. In chronic viral hepatitis B and C, immune attack on hepatocytes bearing viral antigens results in the entry of lymphocytes and other effector cells through the portal tracts from which other lesions may evolve, including interface and lobular hepatitis as well as fibrosis or cirrhosis. Classification systems have been developed in order to provide semiquantitative grading of necroinflammation and staging of fibrosis and include the Scheuer, Batts and Ludwig, Ishak, and METAVIR systems. This review provides an historical perspective on histopathological methods of analyzing chronic hepatitis, describes the essential criteria of each of the major scoring systems and discusses problems related to sampling error, observer variation, and specimen size.