- Urothelial Carcinoma (Transitional Cell Carcinoma): This is the most common type of bladder cancer. It starts in the urothelial cells lining the bladder. Urothelial cells also line other parts of the urinary tract, so tumors might appear in those areas too.
- Squamous cell carcinoma: It is a cancer that begins in the squamous cells. This type of cancer may form after long term irritation or infection with a tropical parasite called schistosomiasis. When chronic irritation occurs, transitional cells that line the bladder can change to squamous cells.
- Adenocarcinoma: This cancer begins in the glandular cells that are found in the lining of the bladder. Glandular cells in the bladder make mucus and other substances.
- Small cell carcinoma of the bladder: This cancer begins in the neuroendocrine cells.
- Sarcoma: Very rare in the bladder, sarcomas begin in connective tissues like muscle cells.
Bladder cancer is also described based on its invasion into the bladder wall:
- Non-Muscle Invasive Bladder Cancer: The cancer hasn’t spread to the muscle wall of the bladder. Most bladder cancers fall into this category.
- Muscle Invasive Bladder Cancer: The cancer has spread through the bladder lining and into the muscle wall or beyond.