Primary signet-ring cell carcinoma of the urinary bladder.

Summary An unusual case of the signet-ring cell carcinoma of the bladder was reported. A 62-year old Japanese male had a three-month history o f intermittent, painless and gross hematuria. He was found to have a small egg-sized bladder tumor near the right ureteral orifice. A cytologic diagnosis o f signet-ring cell carcinoma was made on a bladder washing and was confirmed by cytosco pic biopsy and surgical specimens.