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

A 71-year-old man complained of dyspnea and general fatigue. His blood tests showed severe renal dysfunction. Computed tomographic scan, bone scintigram, and cystoscopy revealed primary signet ring cell carcinoma of the urinary bladder with multiple bone metastases (cT2N0M1). As the general condition of the patient was poor, nephrostomy was performed. He died one month after the diagnosis due to cancer progression. The prognosis of signet ring cell carcinoma of the bladder is poor because many cases presented at an advanced stage. Fifty cases of signet ring cell carcinoma in the urinary bladder reported in Japan are reviewed.