Small cell carcinoma of the bladder: Review of pathogenesis, presentation, and management.

Small cell carcinoma of the bladder (SCCB) is a rare, aggressive malignancy that accounts for less than 1% of all bladder cancers. In this report, we highlight the clinical manifestations of SCCB (including epidemiology, cystoscopic and imaging findings), summarize insights into the molecular mechanisms underlying its pathophysiology, detail current methods of staging, review local and systemic treatment, and explore novel agents currently in clinical development. Most of the regimens used for SCCB treatment are extrapolated from small cell lung cancer, a more common cancer that shares the neuroendocrine and aggressive clinical phenotype of SCCB. Greater preclinical research can help to elucidate pertinent similarities and differences between SCCB and other neuroendocrine cancers as well as reveal new therapeutic targets, while increased participation of patients with SCCB in clinical trials may provide additional treatment options for patients with this aggressive cancer.