Granulomatous cholangitis in chronic hepatitis C: A new diagnostic problem in liver pathology

Abstract

A case of chronic hepatitis C at the pre-cirrhotic stage complicated with hepatocellular carcinoma is reported. The patient, a 64 year old female, showed elevated levels of serum alkaline phosphatase and immunoglobulin M. Antimitochondrial antibodies were negative by indirect immunofluorescence. Western blotting using beef heart mitochondria and recombinant polypeptides coding for mitochondrial antigens revealed that the patient's serum was positive only for the E2-subunit of the branched chain ketoacid dehydrogenase complex. In the non-neoplastic liver, chronic non-suppurative cholangitis surrounded by epithelioid granuloma, resembling the granulomatous destructive cholangitis of primary biliary cirrhosis, was found. The damaged bile ducts were immunohistochemically minimally positive or ambiguous for HLA-DR, and their expression of the E2-subunit of the pyruvate dehydrogenase complex E2 (PDC-E2) was diffuse or granular, and not typical of primary biliary cirrhosis. There was no bile duct loss, and orcein-positive copper binding granules reflecting chronic cholestasis were negative in periportal hepatocytes. The overall features in this case were consistent with primary biliary cirrhosis presenting an infrequent profile of antimitochondrial antibodies and atypical expression of HLA-DR and PDC-E2 on biliary epithelial cells, with late superimposition on chronic hepatitis C. However, it is also possible that this is a case of chronic hepatitis C with hepatitis-associated bile duct damage accompanied by granulomatous reaction. Either way, this case raises new diagnostic issues in the differential diagnosis of chronic liver diseases presented with granulomatous cholangitis.