A case of unresectable intrahepatic cholangiocarcinoma with a germline BRCA1 mutation

Intrahepatic cholangiocarcinoma (ICC) is a malignant liver tumor with poor prognosis. Various mutations in cancer-predisposing genes have been reported in ICC, and germline BRCA1/2 mutations, which are the causative genes for hereditary breast and ovarian cancer syndrome (HBOC), have been reported in many patients with ICC. Here, we report a case of unresectable ICC with a germline BRCA1 mutation. A 73-year-old man was found to have a mass in the left lobe of the liver on abdominal ultrasonography during a medical check-up and was referred to our institution. Contrast-enhanced computed tomography revealed a 30-mm mass with a delayed enhancement pattern, tumor invasion into the major blood vessels, and enlarged regional lymph nodes. Ultrasound-guided percutaneous tumor biopsy revealed a well-differentiated adenocarcinoma, and the patient was diagnosed with clinical Stage IIIB ICC. Systemic chemotherapy with gemcitabine and cisplatin was initiated because of the unresectable nature of the disease. Regarding family history, his eldest daughter was diagnosed with HBOC with a germline BRCA1 mutation at the time of breast cancer surgery, and she developed pancreatic cancer seven years later. The patient underwent BRCA1 single-site analysis and was diagnosed with HBOC with a germline BRCA1 mutation.