Topographical immunohistochemical expression of bcl-2 protein in human liver lesions

Immunolocalization of the bcl-2 protein was investigated in 60 hepatocellular carcinomas, 10 cholangiocarcinomas. 15 metastatic adenocarcinomas as well as in 37 non-neoplastic liver lesions. The three-step immunoperoxidase method was performed in archival, routinely processed material. bcl-2 protein was not identified either in neoplastic, dysplastic or normal hepatocytes, whereas it was observed in bile ductules and small bile duct epithelia, but not in the epithelium lining large bile ducts. All cases of cholangiocarcinoma and 60% of metastatic adenocarcinomas were bcl-2 positive. bcl-2 appears to be an additional marker in distinguishing hepatocellular carcinoma from cholangiocarcinoma or metastatic adenocarcinoma. Also, bcl-2 does not seem to be involved in human liver hepatocyte survival.