Neuroendocrine tumor of the cystic duct.

Neuroendocrine tumours of the extrahepatic bile ducts are extremely rare with less than 70 cases having been reported in the literature. Neuroendocrine tumours are neoplasms of variable malignant potential that arise from the embryonic neural crest cells. They most commonly occur in young females and usually present with painless jaundice. Preoperative diagnosis is seldom made and neuroendocrine tumours are usually incidentally found during abdominal surgical intervention for other indication. Due to their indolent biological behaviour aggressive surgical treatment is recommended. We present a case of an incidentally discovered neuroendocrine tumour of the cystic duct in a 41 year old woman following laparoscopic cholecystectomy for symptomatic gallbladder microlithiasis. The present case is the 8th case of cystic duct NET and the 63rd of extrahepatic bile duct NET. While a rare location for a NET, it is important to report cases of biliary tract neuroendocrine tumours in order for their pathogenesis and physical history to be clarified.