Small cell carcinoma of the urinary bladder: A rare and aggressive tumor

Abstract

The authors describe a case of small cell neuroendocrine carcinoma (SmCC) of the urinary bladder in a 60-year-old woman who presented in the Emergency Department with macroscopic hematuria and pelvic discomfort. Computed tomography revealed a broad-based polypoid tumor on the posterior wall of the bladder, infiltrating both ureters with bilateral hydronephrosis. After an attempt of transurethral resection, the pathology revealed a malignant, non-urothelial tumor, and the patient was referred to our center. Magnetic resonance imaging performed for better characterization and local staging, confirmed an aggressive tumor with perivesical fat invasion. SmCC is a rare type of bladder tumor with clinical and macroscopic presentation similar to urothelial carcinoma. Radiologically it is usually an aggressive tumor, with advanced disease at the initial diagnosis. The clinical and radiological features of bladder SmCC are revised, including a discussion on the utility of immunohistochemical markers.