Late malignancy in bowel segments exposed to urine without fecal stream

This study was constructed so as to screen malignant transformation after uroenteric reconstructions using bowel segments exposed to urine without fecal stream for more than 10 years.

Follow-up data were available for 186 patients who underwent various uroenteric reconstructions using bowel segments exposed to urine without fecal stream for more than 10 years. There were 68 eligible patients with isolated rectosigmoid bladder, 23 with bladder augmentations (15 ileocystoplasty and 8 colocystoplasty), 57 with ileal ureter, and 38 with ileal loop conduit. Besides routine laboratory and radiologic investigations, urine for cytology was obtained from all patients. Moreover, endoscopy and random biopsy of the part of bowel exposed to urine were carried out in all patients.

Uroenteric malignancy was diagnosed in 4 patients (2%): 2 adenocarcinoma in an isolated rectosigmoid bladder, 1 transitional cell carcinoma following augmentation colocystoplasty, and 1 squamous cell carcinoma after ileal ureter. None of the patients developed tumors in ileal loop conduits.

Malignant changes do not only occur after ureterosigmoidostomy but are also observed after different uroenteric reconstructions not exposed to fecal stream. Hematuria, ureteral obstruction, and abnormal urine cytology are warning signs of malignancy. Routine cytology is recommended at least yearly beginning 10 years after surgery.