Carcinogenesis and the use of intestinal segments in the urinary tract.

Intestinal conduits appear to have a low risk of malignancy. The increased risk of neoplasia after ureterosigmoidostomy is well known and may be multifactorial. Other forms of urinary reconstruction and diversion may also increase the risk of cancer. The reports of adenocarcinoma after ileocystoplasty are striking, as the intact ileum rarely undergoes malignant change. Long-term surveillance of patients after urinary reconstruction with intestinal segments is therefore mandatory.