Histological changes in ileal conduits.

The histological appearances of 20 excised ileal conduits are described, 9 of which had been present for more than 10 years. Partial and subtotal villous atrophy associated with a chronic inflammatory infiltrate was seen in all cases. The more severe changes were seen adjacent to the stoma and ureteral orifices, and in the older conduits. The muscularis mucosa was thickened and splintered, and the submucosa showed edema and lymphatic dilatation. These appearances could not be related to the presence of infection or obstruction. The cause of the morphological abnormalities is likely to be multifactorial but the changes are not premalignant. The 2 carcinomas seen were recurrences from primaries elsewhere in the urinary tract.