Cellular Classification of Bladder Cancer
More than 90% of bladder carcinomas are transitional cell carcinomas derived from the uroepithelium. About 2% to 7% are squamous cell carcinomas, and 2% are adenocarcinomas. Adenocarcinomas may be of urachal origin or nonurachal origin; the latter type is generally thought to arise from metaplasia of chronically irritated transitional epithelium. Small cell carcinomas also may develop in the bladder.[2,3] Sarcomas of the bladder are very rare.
Pathologic grade of transitional cell carcinomas, which is based on cellular atypia, nuclear abnormalities, and the number of mitotic figures, is of great prognostic importance.
- Al-Ahmadie H, Lin O, Reuter VE: Pathology and cytology of tumors of the urinary tract. In: Scardino PT, Linehan WM, Zelefsky MJ, et al., eds.: Comprehensive Textbook of Genitourinary Oncology. 4th ed. Philadelphia, Pa: Lippincott Williams & Wilkins, 2011, pp 295-316.
- Koay EJ, Teh BS, Paulino AC, et al.: A Surveillance, Epidemiology, and End Results analysis of small cell carcinoma of the bladder: epidemiology, prognostic variables, and treatment trends. Cancer 117 (23): 5325-33, 2011. [PUBMED Abstract]
- Fahed E, Hansel DE, Raghavan D, et al.: Small cell bladder cancer: biology and management. Semin Oncol 39 (5): 615-8, 2012. [PUBMED Abstract]