Carcinoid tumors of the colon and rectum

C ARCINOID or argentaffin tumors are recognized as not infrequently occurring tumors of the appendix and small intestine.Their pathological features and their clinical behavior have become well known and are the subject of a number of excellent published reviews.'. 8 , 13. 19, 31, 37 In 1941, Ashworth and Wallace called attention to their widespread distribution in the gastrointestinal tract and related organs and noted their occasional occurrence in unusual situations.Stout,'B in 1942, collected reports of twenty carcinoids primary in the large bowel and reported six rectal carcinoids, emphasizing certain peculiar histological features.More recently, Pearson and Fitzgerald have reviewed the literature with respect to carcinoids of the rectum only, finding twenty-nine reported cases and adding three cases that came under their observation, two of which were clinically malignant tumors.The group studied in this laboratory includes another six.Carcinoid tumors involving portions of the large bowel other than the rectum have received somewhat less attention, although several reports were noted by Stout,& and six case reports have been published since his