Well-Differentiated Neuroendocrine (Carcinoid) Tumors of the Extrahepatic Biliary Ducts

Abstract

Primary, well-differentiated neuroendocrine (carcinoid) tumors of the extrahepatic biliary ducts are an uncommon cause of biliary obstruction. As compared to cholangiocarcinomas, which are more commonly seen at this location, these tumors tend to behave less aggressively, and only one-third metastasize. Tumor size (>2 cm) appears to be the best predictor of aggressive behavior. Surgery is the mainstay of treatment and complete resection offers prolonged disease-free survival. Accurate preoperative diagnosis is therefore important and can be made by examining brush cytology specimens obtained during endoscopic retrograde cholangiopancreatography and/or endoscopic ultrasound-guided fine-needle aspiration. It is important to keep this entity in mind, especially when examining cytologic or small biopsy specimens, so that appropriate immunohistochemical stains can be used to arrive at the correct diagnosis.

Primary perihilar bile duct neuroendocrine tumor: a case report and review of the literature

“…However, due to the frequent submucosal location of the tumors, cytological brush sampling exhibits a notable falsenegative rate. Hence, the definitive diagnosis of the majority of B-NENs relies on postoperative histopathology and immunohistochemical findings [13].…”

Primary extrahepatic biliary neuroendocrine tumor: a case report

“…To date, only two EBNETs were diagnosed preoperatively based on endoscopic biopsy results [ 6 , 7 ]. Difficulty in diagnosing EBNETs lies in their difficult to access location, whereas endoscopy appears to have the best results [ 1 , 6 , 7 ]. Diagnosis by brush biopsy has been previously described but has a high incidence of false negativity due to the largely submucosal nature of these tumors [ 3 ].…”

“…Gastrointestinal neuroendocrine tumors (NETs) are rare neoplasms that arise from Kulchitsky (enterochromaffin) cells. Those cells are found in highest proportion in the small intestine, and rarely within the hepatobiliary tract [ 1 ]. Extrahepatic biliary neuroendocrine tumors (EBNETs) are among the rarest primary sites of NETs with a reported incidence of 0.32%, and only 150 cases reported in the literature since its description in 1959 with a 1.7:1 female-to-male ratio [ 2 , 3 ].…”

Neuroendocrine Tumours of Extrahepatic Biliary Tract: Series of Four Cases with Literature Review

“…However, biliary NETs have been found to be hyper dense in arterial phase and more localized to the primary location without invading the surrounding structures than their cholangiocarcinoma counterparts [13]. Brush cytology specimen obtained via ERCP, Percutaneous transhepatic cholangiography or endoscopic ultrasound guided FNAC can provide the histological diagnosis but this potential is marred by the high false negative rates owing to the submucosal location of these tumours [4,14]. Achieving preoperative tissue diagnosis is desirable in NETs as it helps in selecting the modality for further staging in the form of DOTA PET and/or FDG PET scans.…”