Liver biopsy assessment in chronic viral hepatitis: a personal, practical approach.

The terminology for assessment of chronic viral hepatitis in liver biopsy specimens has become confusing with the proliferation of grading and staging schemes that have paralleled the rise of the hepatitis C epidemic and the importance of mixed viral infections. This review represents a personal approach to the interpretation of these biopsy specimens, aiming at clarifying and simplifying the important points for the general pathologist confronted by these diagnostic dilemmas. The most commonly used schemes-Ishak modification of the Knodell 'hepatic activity index', Scheuer, Metavir, Batts-Ludwig classifications-are presented with evaluation of their pros and cons. Which scheme is selected is less important than the consistent use of a single scheme and the clear naming of that scheme in pathology reports. The importance and clinical implications of identifying severe necroinflammatory activity in the form of 'confluent necrosis' is discussed. Pathologists must also be clear about assessing concomitant diseases, in particular, alcoholic or non-alcoholic fatty liver disease, and be aware that grading/staging schemes for chronic hepatitis do not apply to mixed disease conditions. Other important features to be evaluated in all chronic hepatitis biopsy specimens include iron (which may represent hereditary hemochromatosis or secondary uptake) and neoplasia-associated changes, namely large cell change and small cell change; these findings and their clinical import are updated and reviewed. Sample approaches to composing useful diagnostic reports are also presented.