Liver transplant pathology - messages for the non-specialist.

This review, based on a presentation at the BDIAP meeting in London 2008, aims to guide histopathologists working outside transplant centres in the differential diagnosis of late post transplant liver biopsies. It focuses on the histological patterns of the late post transplant complications - autoimmune hepatitis, acute and chronic rejection, recurrent viral hepatitis, and biliary disease. Analysis of the character and distribution of inflammatory infiltrate, bile duct changes, and fibrosis by the histopathologist must then be set within the clinical context to arrive at the most appropriate diagnosis. For this reason, review of the biopsy at the transplant centre is recommended. In a broader context, the tabulation of diagnostic features in chronic inflammatory liver diseases produced by the Banff Working Group can, with the exception of rejection, usefully be applied outside the transplant setting.