Signet-ring-cell carcinoma of stomach metastatic to the bladder: A case report with cytological and histological correlation and literature review

Background. Bladder involvement by a secondary tumor is fairly rare and an uncommon source of bladder metastasis is the stomach. Case report. The authors report a case of a 38-year-old man with a bladder metastasis from a gastric signet-ring-cell (SRC) adenocarcinoma who presented with ematuria. The clinical history and the presence of SRCs in the voided urinary cytology and histologically in the suburothelial connective, with an overlying intact urothelium suggested a diagnosis of bladder metastasis from gastric carcinoma. Conclusion. Bladder involvement by a secondary tumor is very rare, and a SRC carcinoma metastatic to the bladder, albeit extremely rare, should be considered in the differential diagnosis.