Cholangiocellular carcinoma associated with multiple liver cysts.

A 46-year-old woman visited our outpatient clinic complaining of dull right hypochondrial pain. Ultrasonography revealed four cysts in the right lobe of the liver. Arteriography and CT could not determine whether these cysts were benign or malignant. Because one of these cysts contained chocolate-colored fluid, amebic abscess was suspected, and the cyst was drained. No amebae were found in the cultured exudate, and fresh bleeding continued; therefore, laparotomy was performed. A tumor was present on the surface of the liver. Right lobectomy was performed. The resected specimen contained one nonepithelialized cyst which was invaded by surrounding cholangiocellular carcinoma and three epithelialized cysts. Preoperative diagnosis of this kind of cholangiocellular carcinoma seems to be very difficult. Recently cholangiocellular carcinoma associated with developmental cysts has been classified as a new entity different from cystadenocarcinoma. Cholangiocarcinoma, which belongs to this group, seems to deserve special attention.