A Rare Case of Small Cell Carcinoma of the Urinary Bladder.

Abstract

Small cell carcinoma of the bladder is a rare type of bladder malignancy. Based on most of the existing studies, there is an observed male predominance, usually in their sixties or seventies, and they are more likely to have a history of smoking. Additionally, there is a higher predilection for Caucasians (versus non-Caucasians). The most common presenting complaint is painless macroscopic hematuria. However, other presenting symptoms also include dysuria, difficulty voiding, weight loss, abdominal pain, nocturia, and urinary frequency. It is not uncommon to have a history of frequent urinary tract infections, ureteral obstruction, and paraneoplastic syndromes. Cystoscopy is the "gold standard" for evaluation of urinary tract lining, especially in conjunction with narrow-band imaging and biopsy. Transurethral resection of the bladder tumor (TURBT) is the next step in diagnosis and treatment that allows to precisely evaluate pathology and the extent of bladder wall involvement, and is a sufficient surgical approach for the treatment of non-muscle invasive tumors. Once tumor pathology is confirmed, a treatment plan is determined based on the staging. Although both lung and bladder small cell carcinoma have similarities in pathogenesis, genomic alterations in small cell carcinoma of the bladder are more similar to that of urothelial cancer rather than small cell lung cancer. As this is a rare subtype and only a few reported cases are available, no standard treatment regimen has been established. In localized disease, neo-adjuvant platinum-based chemotherapy with cystectomy has been shown to provide the best result in retrospective studies. As this type of cancer has a poor prognosis, in metastatic disease, palliative chemotherapy is offered. Here we present one such case of small cell carcinoma of the bladder and review the current literature.