The relationship between fistulas in Crohn's disease and associated carcinoma. Report of four cases and review of the literature.

Patients with carcinoma involving chronic fistulizing Crohn's disease may have developed the malignancy due to chronic epithelial irritation at either end of the fistula tract. Alternatively, the carcinoma may be the cause of the fistula. Examples of each type of relationship are presented in the reports of four patients from our institution and supported by a review of the literature. The diagnoses of such carcinomas are often delayed due to lack of specificity of symptoms and signs. A high index of suspicion and regular surveillance of high-risk patients are recommended.