Abstract
Combined hepatocellular-cholangiocarcinoma (HCC-CC) is rare, constituting much less than 5% of all primary liver cancers. Its dual histologic and cytologic differentiation may be a major problem in the differential diagnosis of fine needle aspiration biopsies (FNABs) of the liver. We describe two cases of combined HCC-CC, both examined initially by FNAB. Cytologic smears were markedly cellular, with a population of slightly to moderately pleomorphic neoplastic cells, often arranged in cohesive cords and columns resembling anastomosing hepatic plates. Many of these cells had centrally placed nuclei and a moderate amount of granular, eosinophilic cytoplasm. Other cellular groups were arranged in acinar formations, with eccentric nuclei and intraluminal and cytoplasmic mucin production. Both types of cells were positive for cytokeratin and carcinoembryonic antigen; in one case the carcinoma cells were also focally positive for α-fetoprotein. Although these neoplasms may pose diagnostic challenges, our experience suggests that HCC-CC may be suspected or even diagnosed by FNAB.