[A case of small cell neuroendocrine tumor occurring at hilar bile duct]

Neuroendocrine tumors of the extrahepatic biliary tree are extremely rare malignancies accounting for 0.2-2.0% of all gastro-intestinal carcinoid tumors. Neuroendocrine tumors obstructing the biliary tree are extremely difficult to diagnose preoperatively and nearly impossible to differentiate from cholangiocarcinoma. Statistically, the most common anatomic location in the biliary tree is the common bile duct, followed by the perihilar region. Herein, we present a case of a small cell neuroendocrine carcinoma of the hilum in a 79-year-old man following laparotomy. To our knowledge, this is the first case of small cell type neuroendocrine carcinoma of hilar bile duct reported in Korea.