Carcinoids of the colon and ileocecal region: a statistical evaluation of 363 cases collected from the literature.

The colon and ileocecal region are rare sites of origin for gastrointestinal carcinoids. This study evaluates the present status and characteristics of carcinoids of these particular sites in a statistically reliable number of cases and offers fundamental information for future analysis and treatment of these neoplasias. A total of 363 cases of colonic and ileocecal carcinoids were collected from international literature and evaluated in the computer analyzing system. For the final evaluation, 279 cases with sufficient information, consisting of 203 colonic and 76 ileocecal carcinoids, were selected for analysis. In addition, 69 cases of atypical varieties in identical sites were studied for a comparison of 5-year survival rates with the 279 ordinary colonic and ileocecal carcinoids. The characteristic features of colonic and ileocecal carcinoids included: 1) a female preponderance and older age group in the ileocecal carcinoids; 2) a higher incidence of carcinoids in the cecum as compared to those of the rest of the colon followed by the ileocecal region; 3) a high incidence of palpable abdominal tumors resulting from a tendency of the tumors to be large (89.7% were over 2 cm); 4) a high incidence of metastases (61.3%); 5) a high incidence of Grimelius argyrophilia (100.0%) and argentaffin cell type (85.7%) in ileocecal carcinoids; 6) a low detection rate of serotonin in immunohistochemical (66.7%) and laboratory (68.7%) evaluation; and 7) a low postoperative 5-year survival rate (40.5% by the crude calculation method and 65.3% by the Kaplan-Meier method). The present statistical evaluation disclosed a considerable delay in detecting colonic and ileocecal carcinoids resulting in extensive and aggressive surgical treatments and poor postoperative outcomes.