Neuroendocrine tumors of the gastrointestinal tract: Case reports and literature review.

Neuroendocrine tumors (NET) previously called carcinoid tumors are neoplasms of enterochromaffin/neuroendocrine cell origin which display neurosecretory capacity that may result in the carcinoid syndrome. The annual incidence of patients with NET is 8.4 per 100000; yet many NET remain asymptomatic and clinically undetected. A majority of NET follows a benign course; however, some will display malignant characteristics. NET most commonly occur in the gastrointestinal tract (67%) and bronchopulmonary system (25%). Gastrointestinal NET occur within the stomach, small intestine, liver, and rectum. We report a retrospective study of 11 subjects: Eight with benign carcinoid tumors: duodenal bulb (n = 2), terminal ileum (n = 1), sigmoid colon (n = 2), and rectum (n = 3); three with malignant carcinoid: liver (n = 1) and intra-abdominal site (n = 2). The diagnosis, endoscopic images, outcome, treatment and review of the literature are presented.