Primary synchronous mesenteric neuroendocrine tumors: Report of a rare case with review of literature.

Most neuroendocrine tumors of the gastrointestinal tract are traditionally termed "carcinoid tumors." More than 90% of all gastrointestinal carcinoids are located in the appendix, small intestine, rectum, and mesenteric carcinoids are rare. Even when invasive, most carcinoids are relatively indolent and display minimal histological pleomorphism. A minority of these tumors is clinically more aggressive and has a less differentiated histological pattern. Carcinoid tumors of the intestine frequently invade the mesentery, but a primary carcinoid of the mesentery is extremely rare. Mesenteric carcinoid tumors can go unrecognized due to nonspecific symptoms. We report an unusual case of two large primary mesenteric carcinoid tumors in a 38-year-old male who had excellent recovery following surgery. A complete histopathologic, immunohistochemical, and radiologic workup enabled correct diagnosis in this case.