Diagnostic issues in liver transplantation pathology.

Liver biopsy is used to determine the pathogenesis of liver dysfunction after liver transplantation. One or more causative factors may be identified on biopsy. The pathologist must be familiar with the histopathology of acute rejection to differentiate it from other potential complications, including biliary obstruction, intercurrent cytomegalovirus hepatitis, or recurrent disease. Consensus documents from the Banff international panel provide useful guidelines for the appropriate grading of acute and chronic rejection.