A rare case of intrahepatic cholangiocarcinoma with tumor thrombus in the bile duct.

Intrahepatic cholangiocarcinoma (ICC) is a refractory liver malignancy; however, as its histological characteristics have been clarified, a good operative strategy for the subtypes of ICC can be expected. A 72-year-old woman was diagnosed with a large primary liver cancer with biliary tumor thrombus (BTT) and obstructive jaundice. An enhanced imaging modality showed hypervascular ICC or combined hepatocellular carcinoma (HCC). As her liver functional parameters permitted major hepatectomy, preoperative biliary drainage was performed, followed by a radical left hepatectomy accompanied by tumor thrombectomy with D2 lymphadenectomy. During the operation, the BTT was found to have widely spread into the right hepatic duct and the common bile duct and was histologically diagnosed as an adenocarcinoma. As ductal cancer invasion was not macroscopically observed, the planned operation was completed. The postoperative histological diagnosis was determined by discussion to be a rare mass-forming ICC with BTT. Her postoperative course was uneventful, and a 1-year survival without tumor relapse was observed with adjuvant chemotherapy. In the field of biliary surgery, although advanced ICC still has a poor prognosis, curable surgical intervention is possible for specific findings, such as BTT and HCC with BTT.