Carcinoid tumors of the alimentary tract. I. Radiographic diagnosis.

This paper is based on a retrospective analysis of the radiographic findings in 18 new proven cases of carcinoids of the gastrointestinal tract. Examples of lesions involving different segments together with a detailed review of the pertinent literature are provided. Background information regarding the malignant potential of all carcinoids with particular reference to invasiveness, size, site, and symptomatology is discussed. Depending on the time of the examination during their development, carcinoids present either as smoothly defined, mostly small intramural nodules, or as large infiltrating and ulcerating malignant looking tumors. When mesenteric infiltration is present, a more specific combination of findings composed of submucosal nodules, separation of loops, and localized kinking may be seen. The demonstration of an isolated, sharply contoured defect does not exclude malignancy. The less common radiographic manifestations of tumoral calcifications and bony metastases are reviewed and illustrated.