Micro-lymph node metastasis in intrahepatic cholangiocarcinoma showing pathological complete response to primary tumor and intrahepatic metastasis treated by gemcitabine plus cisplatin chemotherapy and radical surgery

Surgical resection is the only curative treatment option for achieving long-term survival in biliary tract cancer patients. However, regional lymph node dissection in intrahepatic cholangiocarcinoma (ICC) is controversial. Herein, we document our experience with a 76-year-old man who had a 70 mm mass in liver segments 6 and 7 and a 10 mm mass in liver segment 3, which were diagnosed as poorly differentiated adenocarcinomas by needle biopsy. Lymphadenopathy was not evident on multidetector computed tomography scanning. Twenty courses of gemcitabine plus cisplatin chemotherapy were administered to the patient. The tumor masses shrunk and exhibited a partial response to chemotherapy as per the Response Evaluation Criteria in Solid Tumors version 1.1. Although tumor markers were all within normal limits, renal function parameters showed deterioration due to systemic chemotherapy. Therefore, continuing systemic chemotherapy was deemed unfeasible and we decided to perform a radical resection using extended posterior segmentectomy and partial liver resection with regional lymph node dissection. Postoperative histopathological examination revealed complete response of primary tumor and intrahepatic metastases; however, a micro-lymph node metastasis was found. The patient is still alive, without recurrence, more than 30 months after treatment initiation and 15 months after surgery. Even if remarkably effective pathological findings may be observed in the primary tumor, there are cases in which a micro-lymph node metastasis remains that are not identified on imaging examinations. Thus, regional lymphadenectomy may be useful in obtaining the exact state of disease progression and evaluation of chemotherapeutic effect in radical surgery.