Immunocytochemical localization of polyclonal carcinoembryonic antigen in hepatocellular carcinomas.

Hepatocellular carcinomas exhibit a unique canalicular immunocytochemical staining pattern with polyclonal antibodies directed against carcinoembryonic antigen (pCEA). The use of this method to facilitate a definitive diagnosis of hepatocellular carcinoma on fine needle aspirates of the liver was evaluated using aspirates and the corresponding core biopsy samples from nine cases. Immunoperoxidase staining with pCEA produced an identical canalicular staining pattern in 6 (66%) of 9 aspirates and 6 (75%) of 8 biopsy samples. The negative results in three aspirates may be due to their lack of the tissue fragments necessary to show this staining pattern. These findings indicate that the expression of this unique immunocytochemical staining pattern may aid in the diagnosis of primary hepatocellular carcinoma by fine needle aspiration cytology.