Colonic polyps and adenocarcinoma complicating ureterosigmoidostomy: report of a case.

A case of bilateral juvenile polyps and unilateral adenocarcinoma at the ureterocolic junctions occurring 40 years after ureterosigmoidostomy for exstrophy of the bladder is reported. Although adenocarcinoma of colon at the anastomotic site represents an uncommon late complication of ureterosigmoidostomy, patients undergoing this form of urinary diversion have a risk of developing colonic carcinoma that is 100 to 550 times greater than the normal population. Moreover this complication is being reported with increasing frequency in the literature. Different pathogenetic factors may play a role in carcinogenesis, but none has been satisfactorily proven. We suggest the possibility that polyps developing at the site of a ureterocolic junction may represent precancerous lesions.