Small-cell neuroendocrine tumor of the bladder: Unexpected long-term survival with carboplatin-etoposide therapy in a patient with metastatic stage disease.

Neuroendocrine small-cell bladder cancer is an extremely rare and aggressive entity, it constitutes <1% of all bladder malignancies. The small-cell neuroendocrine histological variant has a worse prognosis than the classical subtypes. A case of a 53-year-old female consulting with gross hematuria is presented. Cystoscopy revealed a solid aspect lesion involving the posterior wall and dome that was resected. Histopathological findings showed small-cell pure variant carcinoma, high grade, with lymph, vascular, and perineural infiltration, infiltrating the muscle layer. The extension study made by hole body computed tomography scan, showed evidence of multiple lymph nodes and multiple visceral radiological involvements, with pulmonary, hepatic, and peritoneal implants. More than 10 years later, after receiving nine cycles of carboplatin-etoposide remains in complete remission and without radiological evidence of the disease. This is, to our knowledge, one of the longest disease-free survival cases in metastatic small-cell bladder cancer published nowadays.