Introduction: Signet-ring cell carcinoma of the urinary bladder can be primary - arising from the bladder wall or urachus remnants - or metastatic from tumors originating in the stomach, colon, or breast. Saphir first described primary signet-ring cell cancer of the urinary bladder in 1955. Less than 100 cases have been reported in the literature since then.
Case report: We report a case of a 45-year-old woman who was admitted with gross hematuria. Cystoscopy revealed a necrotic tumor on the left bladder wall. A transurethral biopsy showed signet-ring cell carcinoma. The bladder tumor was diagnosed as the primary one. Radical cystectomy was performed with ureterosigmoidostomy (Mainz pouch II). Histological examination showed a primary signet-ring cell carcinoma of the bladder (pT3bN0M0). Following surgery, the patient received adjuvant chemotherapy with cisplatin and fluorouracil.
Conclusions: Primary signet-ring cell carcinoma of the urinary bladder is an extremely rare tumor, accounting for approximately 0.24% of all bladder malignances. Patients with this type of cancer generally have a poor prognosis. However, our patient is free of disease 5 years after radical cystectomy.