Primary carcinomas of urinary bladder diverticula

Two cases of carcinoma arising from the urinary bladder diverticulum were found at autopsy. Both patients had hematuria as a chief complaint and were found to have a tumor mass in the bladder on cystoscopic examination. However, owing to various difficulties the tumors could not be diagnosed before death. Autopsy revealed that the tumors in both cases had arisen within diverticula and had grown into the orifice of the diverticula giving the appearance of ordinary bladder tumors. Histological examination showed that in Case 1, two carcinomas, a keratinizing squamous cell carcinoma and a transitional cell carcinoma, had developed separately in a diverticulum. This may be the first case report of two cancers in a bladder diverticulum. There were no metastases in this case. Case 2 had an undifferentiated carcinoma with metastases to many organs including the lung, liver, and lymph nodes.