What type of carcinoma accounts for approximately 90% of bladder cancers?

Urothelial carcinoma, formerly known as transitional cell carcinoma, is the type of carcinoma that accounts for approximately 90% of bladder cancers. This type of cancer arises from the urothelial cells, which line the bladder and are specialized for stretching as the bladder fills. Urothelial carcinoma can occur in various forms, ranging from superficial tumors to more invasive types, but it is predominantly the most common form found in the bladder.

The prevalence of urothelial carcinoma in bladder cancers is significant, reflecting the cellular origin of the bladder lining itself. Understanding this context is crucial for grasping the overall landscape of bladder cancer and its treatment options. Other types of carcinomas, while they do exist, contribute to a much smaller percentage of bladder cancer cases. For instance, squamous cell carcinoma and adenocarcinoma are less common and typically arise under specific etiological circumstances or risk factors, such as chronic irritation or infection. Small cell carcinoma is also rare in the bladder and is more often associated with other sites, such as the lungs. Thus, the distinct association of urothelial carcinoma with bladder cancer prevalence is a key point in oncology practice in relation to diagnosis and treatment strategy.