[Stage pT1 signet ring cell carcinoma of the urinary bladder: a case report]

A case of primary signet ring cell carcinoma of the urinary bladder is described. A 59-year-old man presented with microscopic hematuria, and cystoscopy revealed a white nonpapillary tumor. Histopathological examination of the resected tumor revealed signet ring cell carcinoma and transitional cell carcinoma. Histological depth of invasion was pT1. No adjuvant therapy was performed. Primary signet ring cell of the urinary bladder is a rare tumor with 37 cases reported to date in Japan. We investigated previously reported cases and discussed adjuvant therapies of superficial signet ring cell carcinoma of the urinary bladder.