Early presentation of carcinoma of the small bowel in Crohn's disease ("Crohn's carcinoma"). Case reports and review of the literature.

We report here 3 cases of adenocarcinoma of the small bowel complicating Crohn's disease ("Crohn's carcinoma"). In 2 cases, the adenocarcinoma was discovered in the first attack of enteritis. In only one other case in the literature, a similar presentation was described. A review of 59 reported cases of adenocarcinoma of small bowel in Crohn's disease, together with these 3 cases reveals that: (a) the cancer develops at a younger age than in carcinoma de novo; (b) there is no difference in incidence of carcinoma in the first, second, and third decades after the onset of symptoms of Crohn's disease; (c) in 73% of cases, the neoplasm rose in the ileum; (d) in all but 1 case it developed in inflamed segments of bowel; (e) in 31% of cases the cancer developed in a bypassed segment of bowel. This analysis clearly demonstrates that "Crohn's carcinoma" is a complication in Crohn's disease and not a chance coexistence of two diseases in the same patient.