A case of primary hepatic neuroendocrine tumor with biliary tumor thrombus in the perihilar bile duct treated with curative surgical resection

Abstract

A 60-year-old man became aware of itching and jaundice. Blood tests showed elevated hepatobiliary enzymes and he was referred to our hospital. Contrast-enhanced computed tomography revealed a 50-mm tumor in the left lobe of the liver with strong contrast enhancement, extending into the perihilar bile duct. After endoscopic biliary drainage, he underwent left hemihepatectomy with caudate lobectomy combined with middle hepatic vein and extrahepatic bile duct resection. The resected specimen showed a white hepatic tumor, with a size of 50 × 38mm and a well-defined papillary tumor was expanding into the perihilar bile duct, forming tumor thrombus. Histopathologically, the tumor cells comprising round enlarged nuclei and abundant clear cytoplasm proliferated and were positive for chromogranin A and synaptophysin, and the MIB-1 index was 8%, leading to the diagnosis of primary hepatic neuroendocrine tumor (PHNET) G2. Moreover, immunohistochemical examination revealed that tumor cells were positive for CK7 and CK19, markers of biliary epithelium. The present case was considered to be an extremely rare case of PHNET with tumor thrombus in the perihilar bile duct.