[A case of intrahepatic cholangiocarcinoma difficult to distinguish from metastatic liver cancer].

A 65-year-old woman presented to our department with a liver tumor. She had undergone subtotal colectomy and total hysterectomy for hereditary nonpolyposis colorectal cancer and uterine cancer 14 years prior to diagnosis. An abdominal CT scan revealed a ring-enhancing tumor with portal vein tumor thrombus on the left lobe. With a preoperative diagnosis of intrahepatic cholangiocarcinoma, combined hepatocellular and cholangiocarcinoma, or metastatic liver cancer; we performed an extended left hepatic lobectomy. The histopathological examination showed adenocarcinoma of the liver. The histopathological findings of the liver tumor resembled that of the previous uterine cancer. Immunohistochemical testing was positive for CK7 and negative for CK20, CDX2, PgR, vimentin, and CA125. However, PgR, vimentin, and CA125 were positively stained in the uterine cancer. Based on these findings, the final diagnosis of the liver tumor was primary intrahepatic cholangiocarcinoma.