Small cell carcinoma of the urinary bladder. A clinicopathologic study of five cases.

Aims And Background: Small cell carcinoma of the bladder (SCCB) is a rare entity characterized clinically by an aggressive behavior with a high incidence of systemic metastases. We report the clinicopathologic findings of five cases.

Methods: We reviewed five consecutive patients with SCCB treated at our institute. In each case the following clinical data were recorded: age, sex, presenting symptoms, endoscopically determined location of the tumor, clinical staging, node involvement (if any), site of metastases (if any), treatment, follow-up and outcome.

Results: There were four male and one female patients, age range 42 to 68 years, mean 57.6 years. The clinical presentation was not different from conventional transitional cell carcinoma, with hematuria being the most frequent complaint (four cases). Microscopic examination revealed oat cells in three cases and an intermediate variant in one. At the time of diagnosis the tumors were staged as T3bN2M0, T2N2M0, T4N0M0, T3aN0M0, and T2N0M0. Primary therapy consisted of radical cystectomy alone (one case), transurethral resection (TUR) alone (one case), TUR with chemotherapy (two cases), or TUR with chemotherapy and radiotherapy (one case). Four patients died of progressive disease, with survival from the time of diagnosis ranging from 7 to 16 months (mean, 12.2 months). One patient died of myocardial infarction (unrelated to the primary disease) one month after diagnosis.

Conclusion: Our study indicates that primary small cell carcinoma of the urinary bladder is as aggressive as its pulmonary counterpart and the overall prognosis of this tumor is very poor.