Although surgical resection is the only available treatment to achieve long-term survival in biliary tract cancer, many cases are often identified at an advanced stage at the time of diagnosis. Radiotherapy may be an alternative option to prolong survival in cases with locally advanced unresectable disease. While there are some reports of long-term survival after radiotherapy for unresectable biliary tract cancer, it is rare that clinical symptoms are exhibited by peritoneal dissemination more than 8 years after radiotherapy and that resection can be performed. Our case was a 55-year-old female who had visited with a complaint of jaundice and was diagnosed with primary unresectable hilar cholangiocarcinoma. She received definitve chemoradiotherapy, and repeated receiving maintenance chemotherapy thereafter until clinical manifestation. During follow-up, she was diagnosed with stenosis of the sigmoid colon, which was attributed to peritoneal dissemination of cholangiocarcinoma. We herein report a rare case of primary unresectable hilar cholangiocarcinoma after chemoradiotherapy which was followed by chemotherapy that was controlled for more than 8 years but eventually caused colonic obstruction attributed to peritoneal dissemination.
