Carcinoma complicating Crohn's disease. Report of seven cases and review of the literature.

Seven cases of adenocarcinoma complicating Crohn's disease are reviewed. In three of the patients, small bowel cancers developed in association with reginal enteritis. In four patients, carcinoma of the colon was superimposed on Crohn's colitis. In two of these, the adenocarcinoma infiltrated chronic colocutaneous fistulas. Review of the literature shows an increasing number of reports of carcinoma complicating Crohn's disease, with a total of 36 cases of small bowel cancer and 30 cases of colon cancer previously reported. The significane of these and our own cases is discussed. The possibility of carcinoma must be kept in mind by clinicians following patients with Crohn's disease. Adenocarcinoma complicating Crohn's disease occurs at a younger age, on the average, and in areas similar to the distribution of Crohn's disease rather than the usual distribution of the cancer. Preoperative diagnosis is difficult, but changes in the nature of chronic fistulas should be investigated.