Copy number aberrations in combined hepatocellular carcinoma and cholangiocarcinoma.

Combined hepatocellular carcinoma and cholangiocarcinoma (CHC) is a rare liver cancer which shares unequivocal features of both hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC). A greater awareness of genetic relationship between HCC and CC components is limited. To help characterize this rare liver neoplasm, we described clinicopathologic features and evaluated copy number (CN) changes in this study. A total of 13 cases of CHC were collected. Four paired HCC and CC components from four cases were first subject to genome-wide analysis. Nine target genes were subsequently selected for further analysis using quantitative polymerase chain reaction. The paired HCC and CC components in each case had a concordant trend of CN gain or loss in these nine genes. However, the magnitude of concordant CN gain or loss was different. There were significant differences of CN copies between HCC and CC in each case. We demonstrate genetic divergence between HCC and CC components in CHC.