Neuroendocrine Carcinoma of the Gallbladder Masquerading as a Klatskin Tumor in a 74-Year-Old Male

Neuroendocrine carcinomas represent a heterogeneous tumor entity, which can occur in almost all organ systems of the human body. The worldwide incidence, approximately 0.5– 5/100.000, is low, with almost 70 % occurring in the digestive sys t em , ano the r 20 % be ing d i agnosed in the bronchopulmonary tract. Data from autopsy studies suggest that neuroendocrine tumors are an under-recognized malignancy [3]. Only 0.2 % of all neuroendocrine tumors (NETs) are located in the gallbladder. The most important prognostic factor is the level of proliferation, which determines the tumor grading. Overall, poorly differentiated NETs are aggressive tumors bearing a poor prognosis.