[A Case of Intrahepatic Cholangiocarcinoma and Early Postoperative Recurrences Using Comprehensive Genome Profiling to Implement Effective Treatment].

Subsequent to a medical examination, a 61-year-old male was referred to our hospital with jaundice. He was diagnosed with intrahepatic cholangiocarcinoma involving the hepatic hilum and was referred to our department to undergo a left trisectionectomy of the liver, extrahepatic bile duct resection, and regional lymphadenectomy. He was discharged on postoperative day 39 without liver failure. Two months postoperatively, positron-emission tomography/computed tomography(PET/ CT)indicated recurrences in the bone, and paraaortic lymph node. Gemcitabine and cisplatin combination first-line therapy was administered. Disease progression occurred after 4 courses of therapy. Gene panel testing was performed and the patient was switched to pembrolizumab owing to high microsatellite instability. After 2 courses of pembrolizumab, notable shrinkage of the paraaortic lymph node recurrence was confirmed on computed tomography as well as a partial response. PET-CT revealed disappearance of abnormal accumulation in all lesions at 20 months postoperatively. This has been sustained for 24 months following surgery without remarkable immune-related side-effects.