Small cell carcinoma of the urinary bladder: a clinicopathologic analysis of 64 patients

Background: Small cell carcinoma of the urinary bladder is an uncommon tumor that has been described in case reports or small series. Herein, the authors report a series of 64 patients with small cell carcinoma of the urinary bladder.

Methods: Histologic slides and medical records from 64 patients with small cell carcinoma of the urinary bladder were reviewed for morphologic, demographic, and clinical data. All patients fulfilled the criteria established for small cell carcinoma according to the World Health Organization classification system. The 2002 tumor, lymph node, and metastasis (TNM) system was used for pathologic staging. The correlations of various clinicopathologic characteristics with survival were analyzed.

Results: Patients ranged in age from 36 years to 85 years (mean age, 66 years). The male-to-female ratio was 3.3:1.0. Among patients with clinical information available, 65% had a history of cigarette smoking, and 88% presented with hematuria. All but one patient had muscle-invasive disease at presentation. Thirty-eight patients (59%) underwent cystectomy. Sixty-six percent of patients had lymph node metastasis at the time of cystectomy. Twenty patients (32%) had pure small cell carcinoma, and 44 patients (68%) had small cell carcinoma with other histologic types (35 patients had urothelial carcinoma, 4 patients had adenocarcinoma, 2 patients had sarcomatoid urothelial carcinoma, and 3 patients had both adenocarcinoma and urothelial carcinoma). With a mean follow-up of 21 months, 68% of patients died of bladder carcinoma. None of the clinicopathologic parameters studied (age, gender, presenting symptoms, smoking history, the presence of a nonsmall cell carcinoma component, chemotherapy, or radiation therapy) were associated with survival. No significant survival difference was found between patients who did and did not undergo cystectomy (P = 0.65). Patients who had organ-confined disease had marginally better survival compared with patients who had nonorgan-confined disease (P = 0.06). The overall, 1-year, 18-month, 3-year, and 5-year disease-specific survival rates were 56%, 41%, 23%, and 16%, respectively.

Conclusions: The prognosis for patients with small cell carcinoma of the urinary bladder remains poor, even though the overall survival for patients with bladder carcinoma has improved significantly over the last decade.