There are three main types of bladder cancer. These are named after the cell type in which the cancer first develops.

• The most common type of bladder cancer starts in the urothelial cells in the innermost layer of the bladder wall. This is called urothelial cell carcinoma (or transitional cell carcinoma). More than 90% of cases of bladder cancer start in the urothelial cells.  
• Squamous cell carcinoma starts in the thin, flat cells lining the bladder. About 6–8% of bladder cancers start in squamous cells.
• Adenocarcinoma is a rare type of bladder cancer that starts in glandular cells lining the bladder. Adenocarcinoma occurs in 2% of bladder cancer cases.