Small cell carcinoma of the bladder: a contemporary clinicopathological study of 51 cases

Aims: We present 51 cases of primary small cell carcinoma of the bladder in a clinicopathological study with emphasis on features that aid in the initial recognition and diagnosis of small cell carcinoma of the bladder. Methods and results: The patients were 40 men and 11 women between the ages of 39 and 87 years (mean age 67 years). Clinical data were available in 41 cases. The most common symptomatology was haematuria in 63% of the patients while dysuria was present in 12%. Thirty-eight patients were caucasians; seven patients were Hispanics; two patients were Asian; one patient was African-American; in the three additional patients no racial information was obtained. Biopsy material was obtained in all of the patients. Cystectomy was performed in 20 patients. At diagnosis, clinical stage was as follows: stage I in two (5%), stage II in 18 (44%), stage III in 10 (24%), and stage IV in 11 (27%). Histologically, urothelial carcinoma was present in 70% of the cases, adenocarcinoma in 8%, and squamous cell carcinoma in 10% of the cases. Small cell carcinoma was the only histology present in only 12% of the cases studied. Immunohistochemical studies using chromogranin, synaptophysin and chromogranin were positive in 30-70% of the cases. Conclusions: The present study highlights the unusual phenomenon of pure small cell carcinoma of the bladder and its association with other non-small cell carcinomas in that anatomical location. In addition, the study highlights the different modalities employed to treat patients in whom there is a component of small cell carcinoma of the bladder.