Wang G, et al. - For this investigation, researchers retrospectively studied a large series of bladder small cell carcinoma (SmCC) which is a rare disease from a single institution. This study was conducted on 69 men and 12 women with a mean age of 68 years. SmCC had a worse prognosis only when patients developed metastatic diseases compared to conventional urothelial carcinoma (UC) at similar stages. According to the findings obtained, bladder SmCC was an aggressive disease which was frequently present at an advanced stage. A fraction of SmCC showed a basal molecular subtype, which could underlie its good response to chemotherapy. They suggested that inactivation of the retinoblastoma 1(RB1) gene could be implicated in the oncogenesis of bladder SmCC.