Primary metastatic neuroendocrine small cell bladder cancer: a case report and literature review.

Small cell carcinoma of the urinary bladder (SCCUB) is a rare variant of neuroendocrine nonepithelial tumor. Clinically, SCCUB appears like a flat or ulcerated lesion and microscopically can cause microvascular invasion and necrosis. Small cell cancer, rarely found in the urogenital tract in a primitive form, usually coexists with urothelial bladder cancers. It has an incidence of 0.35-0.7% of all bladder neoplasms and survival at 5 years is estimated to be around 8%. A 60-year-old man who was a smoker was referred to our department with episodes of gross hematuria and pain in the lumbar region. After an extensive transurethral resection of the bladder, including of the muscular layer, the diagnosis of small cell carcinoma of the bladder was made. The neoplastic cells were positive with immunohistochemical staining for chromogranin A, paranuclear reactivity to cytokeratin and neuron-specific enolase. A total-body CT scan revealed lymph node involvement and hepatic, adrenal and lung metastases. Because of the advanced stage it was decided to avoid radical cystectomy and perform chemotherapy. The patient underwent two different cycles of cisplatin chemotherapy following international recommendations, but unfortunately without any response. After palliative therapy, the patient died in January 2010.