Combined hepatocellular-cholangiocarcinoma. Cytologic findings in four cases

Rarely do primary hepatic tumors show mixed hepatocellular carcinoma (HCC) and cholangiocarcinoma differentiation. Histologic criteria for these combined hepatocellular-cholangiocarcinomas (CHCC-C) are not universally agreed upon. Cytologic descriptions of CHCC-C are scarce, yet recognition of this tumor type may have some prognostic significance.

The clinical and cytohistologic findings, including histochemical and immunohistochemical studies, in four cases of CHCC-C were reviewed. The specimens consisted of three needle biopsies of the liver and one bile duct brushing specimen. In all cases the diagnosis of CHCC-C was confirmed by histologic, histochemical and immunohistochemical study.

The reliable diagnosis of CHCC-C on cytologic preparations alone is fraught with difficulty. However, the addition of cell block or core biopsy histologic material, which may serve as a substrate for histochemical and immunohistochemical studies, may permit the diagnosis to be made. Serum markers of HCC, when elevated, may raise the suspicion of hepatocellular differentiation even when it is not suspected based on examination of the cytologic and/or histologic biopsy specimen.