Introduction : Neuroendocrine neoplasm of extrahepatic bile ducts are very rare. The aim of this study to elucidate the clinicopathological characteristics, therapeutic approach and prognosis of these patients.

Methods : The subjects were 16 patients who were diagnosed with neuroendocrine neoplasm or mixed adenoneuroendocrine carcinoma (MANEC) after curative resection. There were 8 ampulla of Vater and 8 non ampulla of Vater (6 gallbladder and 2 distal bile duct).

Results : The female to male ratio was 1.3/1 with mean age of 57.9 years (ranging from 36 to 74). There were 8 cases of incidental diagnosis in health screenings and 2 cases during evaluation for other disease. The most common symptoms were abdominal discomfort (3 pain and 1 dyspepsia) and jaundice (2cases). According to the 2010 WHO classification, 1 patient had NET G1, 5 NET G2, 6 NET G3 and 5 MANEC. G3 and MANEC were small cell type. Pancreatoduodenectomy was performed in 9 patients (1 combined minor hepatectomy), extended cholecystectomy in 6 cases (1 combined pancreaticoduodenectomy and right hemicolectomy) and radical bile duct resection in 1 case. There were no association between OS and DFS with various clinicopathological factors including TNM stage. Ki-67 (cut-off 20%) was only prognostic factor in OS (5year survival: 100% versus 42.3%, p=0.044) and DFS (5year survival: 100% versus 47.6%, p=0.059).

Conclusions : In NET of extrahepatic bile duct, the titer of Ki-67 is more important than TNM according to AJCC, and attention of Ki-67 titer may be needed in treatment of recurrence.