[A Resected Case of Simultaneous Perihilar Cholangiocarcinoma and Hepatocellular Carcinoma with Preoperative Diagnosis].

A 66-year-old man referred to our department due to liver dysfunction, and a close examination revealed wall thickening of the common hepatic duct and a tumor localized in the hepatic S8. Bile duct and liver biopsies resulted in a diagnosis of duplicate perihilar cholangiocarcinoma and hepatocellular carcinoma. Based on the evaluation of the tumor progression, we judged that both tumors could be curatively resected by right hepatectomy plus extrahepatic bile duct resection, and the patient was decided to undergo a primary resection. The postoperative course has no complications, and the final pathology confirmed the above diagnosis. Although there have been many reports of duplicate cancers in patients with risk factors such as a history of hepatitis virus or pancreaticobiliary malunion, it is rare for multiple cancers to originate in the hepatobiliary tract without such risk factors as in this case. In addition, the diagnosis of duplicate cancers requires proof that each cancer did not metastasize from the other and that there is no continuity. In this case, there was no clear continuity and biopsy showed that the tumor was not metastatic lesion from the other, so we could make a preoperative diagnosis of duplicate cancers. When multiple lesions are found, it is important to perform a thorough examination with the possibility of duplicate cancers in mind, and to perform an appropriate surgical resection in consideration of invasiveness.