Small cell urothelial carcinoma remains virtually indistinguishable from its counterpart in the lung. Typically comprised of small, round blue cells with hyperchromatic nuclei and a high nuclear to ...cytoplasmic ratio, these tumors are associated with a very rapid proliferation rate and early metastases. Upstaging at surgery is quite common and is likely the reason for the poor clinical outcomes seen with initial cystectomy. Recent data from the first clinical trial in small cell urothelial cancer suggest more long-term survivors when chemotherapy is given prior to cystectomy. Chemotherapy followed by radiation may be a reasonable alternative in patients with tumors clinically confined to the bladder. However, the frequent presence of other variant histology and carcinoma in situ associated with small cell urothelial cancer may be one reason for the higher relapse rates, including local failure in the bladder, seen with bladder irradiation. Unfortunately, the prognosis in the setting of metastatic disease remains quite poor with an average life expectancy on the order of 1 year. Additional data indicate the incidence of brain metastases may be as high as 50 % in patients with stage 3 or greater tumors, suggesting a subset of patients in which one may consider prophylactic cranial irradiation. However, the numbers of patients treated with these paradigms remain low. Additional work is required to optimize the treatment for patients with this rare malignancy.
