Signet ring cell carcinoma of the bladder and urachus

SummaryPrimary signet ring cell carcinomas (SRCCs) of the bladder and urachus are extremely rare malignancies with only 28 cases of urachal SRCC recorded and bladder SRCC comprising less than 0.1% of bladder malignancies.These rare cases of urothelial SRCC occur largely in men and the disease characteristically presents in patients in their 40s for urachal SRCC and 60s for bladder SRCC. Despite the rarity of the diagnosis, a knowledge of the natural history and management of urothelial SRCC may be valuable as the illness has a number of important differences from conventional bladder TCC.The characteristic pathological findings of sub-mucosal infiltration and spread are often reflected in the clinical presentation and progress of the disease. Bladder SRCC is frequently characterised by a late presentation at an advanced stage, with dysuria the most frequent presenting symptom whilst haematuria is relatively rare. Metastatic spread can occur with retroperitoneal disease that can be difficult to visualise on imaging and can lead to ureteric or small bowel obstruction.As a result of their rarity there is no structured clinical research in urothelial SRCC and the optimal management of early and advanced cases of this rare tumour is unknown. A number of differing chemotherapy regimens have been reported for advanced disease in various case reports and series with variable responses and generally modest benefits.