Primary neuroendocrine tumors of the gallbladder: Ultrasonographic and MDCT features with pathologic correlation

Histologically adenocarcinomas represent 95 % of all gallbladder carcinomas [1]. Conversely, primary neuroendocrine tumors of the gallbladder are extremely rare, representing 0.2 % of all neuroendocrine tumors and only 2 % of all gallbladder carcinomas [2]. The diagnosis of primary neuroendocrine tumors of the gallbladder is usually made during histopathological analysis because no suggestive imaging features that allow discriminating between this specific tumor and the more common gallbladder adenocarcinoma have been described [3]. Because of its rarity, the imaging features of primary neuroendocrine tumor of the gallbladder have received little attention so far. We report herein the ultrasonographic and multidetector row computed tomography (MDCT) findings of two cases of histopathologically confirmed primary neuroendocrine tumors of the gallbladder that presented as large gallbladder masses in association with large metastatic lymph nodes and intrahepatic metastases.