[Primary signet-ring cell carcinoma of the urinary bladder: a case report].

We report a case of signet-ring cell carcinoma of the urinary bladder. A 48-year-old female was hospitalized because of general fatigue, pollakiuria and residual sensation. Renal ultrasonography disclosed bilateral hydronephrosis. The serum level of cretinine was 3.1 mg/dl, and we diagnosed the patient with post-renal failure. Cystoscopic examinations revealed non-papillary sessile tumors in the trigone. Histopathological findings of the biopsy specimen demonstrated signet-ring cell carcinoma. There was no evidence indicating bladder metastasis from the cancer in other organs. The patient died of cachexia 5 months after the diagnosis. She was autopsied, and the diagnosis of signet-ring cell carcinoma of the urinary bladder with metastases in various organs was confirmed. This disease is extremely rare and has a poor prognosis. We review the previous cases reported in the literature.