Carcinoid tumors of the abdomen: CT features.

Carcinoid tumors are rare neuroendocrine neoplasms that belong to a more general category of tumor called the APUDomas. Ninety percent of carcinoid tumors are located in the gastrointestinal tract. Abdominal carcinoid tumors are categorized according to the division of the primitive gut from which they arise. Carcinoid tumors originating from the foregut develop in the gastric wall, duodenum, and pancreas; those originating from the midgut develop from the small bowel, appendix, and right colon; and those originating from the hindgut develop from the transverse or left colon or from the rectum. This report illustrates the computed tomographic appearance of primary and metastatic carcinoid tumors of the abdomen. Among the different organs that may be involved by metastases from carcinoid tumor, special emphasis is placed on the liver.