Colonic metastasis of Klatskin tumor: case report and discussion of the current literature.

We report the case of a 65-year old male patient who initially presented with recurrent episodes of upper abdominal pain, lack of appetite and weight loss. Abdominal ultrasound indicated enlarged intrahepatic bile ducts, abdominal CT scan and ERC were performed and bile duct carcinoma (Klatskin Type III b) was diagnosed. The tumor was located in the segments 2, 3, 4 and 1 with possible invasion of the left intrahepatic portal vein. Both the segments 2 and 3 of the liver were atrophic and displayed a cholestatic bile duct system. Preoperatively an intraductal stent was placed in the left bile duct using ERC to drain the left hepatic lobe. A specimen of the ascites present preoperatively displayed no malignant cells. After evaluation of the preoperatively obtained data left hepatic resection was planned. Following laparotomy we found local peritoneal carcinosis in the ligamentum hepatoduodenale with lymphatic nodules that tested positive for cholangiocellular carcinoma in online pathological examination. In the course of further exploration of the abdomen a solid tumor was detected in the sigmoid colon. Regarding the advanced stage of the neoplasm it was decided to cancel hemihepatectomy and perform sigmoid resection only in order to guarantee uncomplicated intestinal passage. The sigmoid colon was removed by a typical resection technique with end-to-end anastomosis. Histological examination of the resected sigmoid revealed transmural manifestation of a malignant neoplastic process with both a tubular and a solid growth pattern in conformity with metastasis of a Klatskin tumor. The mucosal layer showed no neoplastic alteration. Peritoneal carcinosis is a common phenomenon in the dissemination pattern of advanced-stage Klatskin tumors, yet to our knowledge this is the first case of intramural colonic growth following peritoneal metastasis.