Hepatocellular carcinoma, adenoma, and focal nodular hyperplasia. Comparative histopathologic study with immunohistochemical parameters.

For the evaluation of differential diagnostic parameters, hepatocellular carcinoma (HCC, n = 26), liver cell adenoma (n = 4), focal nodular hyperplasia (n = 8), and secondary liver tumors (n = 15) were studied with histologic and immunohistochemical methods. The study was performed on formalin-fixed, paraffin-embedded tissue sections, and, in some cases, also on frozen sections. The diagnostic contribution of the demonstration of alpha-fetoprotein, alpha-antitrypsin, hepatitis B surface antigen, carcinoembryonic antigen (CEA), and biliary glycoprotein I (BGPI), compared with routine hematoxylin-eosin and reticulin stains was evaluated. For the differentiation between HCC, adenoma, and focal nodular hyperplasia, immunohistochemistry contributed less than the strict application of histologic criteria. Immunohistochemistry of CEA and BGPI, however, appeared to be of help in differentiating between primary and secondary liver tumors as follows: CEA is consistently absent in liver cell tumors, while a bile canalicular staining pattern was seen in 80% of HCC due to the presence of BGPI reactivity.