ABSTRACT
We report here on a case of combined hepatocellular and cholangiocarcinoma (CHC) with neuroendocrine differentiation and sarcomatoid transformation. A 59-year-old male who had had HBV-associated chronic liver disease presented with hepatic masses. The explanted liver showed three small masses, two in the right lobe and one in the left lobe. The largest one in the right lobe was a 2.0 cm sized binodular mass,consisting of a yellowish tan nodule and an abutting reddish brown nodule. Microscopically, the reddish brown nodule was a cholangiocarcinoma (CC) showing neuroendocrine differentiation and sarcomatoid tranformation. The yellowish tan nodule and the remaining two masses were hepatocellular carcinoma (HCC)s. On immunohistochemistry, both the adenocarcinoma and spindle sarcomatoid cells were positive for pancytokeratin, but only the adenocarcinoma cells were positive for chromogranin and carcinoembryonic antigen (CEA). Mitotic and Ki67 labeling indices as well as p53 immunopositivity were significantly increased only in the CC component. We report here on the first case of CHC in which the CC displayed neuroendocrine differentiation and sarcomatoid transformation with high mitotic and Ki67-labeling indices, as well as having p53 overexpression.