Urothelial carcinoma arising within bladder diverticulum—Report of a case and review of the literature

Bladder diverticulum is an outpouching of bladder mucosa through the musculature of the bladder wall. The incidence of bladder diverticulum in Taiwan is about 1.7% in children and 23.4% in adults. Intradiverticular carcinoma of urinary bladder is uncommon. It ranges from 0.8% to 14.3%. Here we report a case of urothelial carcinoma within a bladder diverticulum. A 60-year-old male patient had history of BPH under medical treatment and right ureteral stone treated with extracorporeal shock wave lithotripsy (ESWL). He presented with painless gross hematuria about 3 months after ESWL. Intravenous pyelography showed a filling defect within the bladder diverticulum. Histopathological diagnosis of low grade urothelial carcinoma arising from the bladder diverticulum was made following cystoscopic biopsy. Laparoscopic partial cystectomy was performed with subsequent intravesical chemotherapy. Tumor recurrence was found not from the previous diverticulum but from another area during regular cystoscopy at the 6-month postoperative follow up. He underwent transurethral resection of bladder tumor. Pathology revealed a noninvasive, high grade urothelial carcinoma. There was no further bladder tumor recurrence during the 1-year follow-up period. Bladder-sparing surgery with close cystoscopy follow up for intradiverticular urothelial carcinoma can be applied as an alternative treatment modality.