[A case of primary adenosquamous carcinoma of the liver with formation of colonic fistula].

Primary adenosquamous carcinoma of the liver is generally considered as an extremely rare subtype of cholangiocarcinoma. It has been reported mostly in a form of case studies. As far as we know, there was only one case report on tumor related with biliary fistula. Recently, we experienced a case of primary adenosquamous carcinoma of liver with a formation of tumor-colonic fistula. A 54-year-old man was transferred to our hospital due to liver mass detected by abdominal ultrasonogram. Dynamic computed tomogram of liver showed a large irregular hypodense mass without rim enhancement in right lobe of liver and also suggested a fistula formation between the tumor and hepatic flexure of right colon. Colonoscopic examination showed a large colonic wall defect in hepatic flexure and a friable, nodular mucosa around the defected colonic wall. Extended right lobectomy and right hemicolectomy were done. Microscopically, the tumor was composed of squamous cell carcinoma mainly with foci of the adenocarcinoma component.