Renal metastasis from intrahepatic cholangiocarcinoma.

Metastases to the kidney are extremely rare and intrahepatic cholangiocarcinoma (ICC) is difficult to treat. In this study, we report a case of renal metastasis from ICC. A 72-year-old man who had been followed-up for chronic hepatitis C was diagnosed with ICC in the segment 8 and underwent S8 segmentectomy in 2014. During follow-up, the serum levels of carcinoembryonic antigen and carbohydrate antigen 19-9 were slightly elevated, and abdominal contrast-enhanced computed tomography revealed a low-density mass preceded by rim enhancement in the arterial phase measuring 1.5 × 1.5 cm in the segment 6, and a hypovascular mass measuring 2.2 × 2.0 cm in the upper pole of the left kidney in 2017. He underwent partial hepatectomy and partial nephrectomy. Based on postoperative histological findings combined with immunohistochemical analysis, the tumors both in the liver and kidney were diagnosed as recurrent ICC.