A case of a large cholangiolocellular carcinoma.

Cholangiolocellular carcinoma (CoCC) is a rare malignant primary liver tumor that is considered to originate from the canals of Hering, where hepatic progenitor cells are located. CoCC has various clinicopathological findings, therefore it is difficult to describe a clear diagnostic criteria for CoCC. Reported is a case of a large CoCC in a 45-year-old Japanese woman, which could not be preoperatively diagnosed as CoCC. The final diagnosis of CoCC was determined by pathological observation. Since both the biological behavior and diagnostic criteria of CoCC remain unclear, it is necessary to accumulate more information on CoCCs in order to elucidate these characteristic findings.