Types of bladder cancer
Urothelial carcinoma (transitional cell carcinoma)
Urothelial carcinoma, also known as transitional cell carcinoma (TCC), is by far the most common type of bladder cancer. In fact, if you have bladder cancer it’s almost certain to be a urothelial carcinoma. These cancers start in the urothelial cells that line the inside of the bladder.
Urothelial cells also line other parts of the urinary tract, such as the part of the kidney that connects to the ureter (called the renal pelvis), the ureters, and the urethra. People with bladder cancer sometimes have tumors in these places, too, so all of the urinary tract needs to be checked for tumors.
Other types of bladder cancer
Other types of cancer can start in the bladder, but these are all much less common than urothelial (transitional cell) cancer.
Squamous cell carcinoma
In the US, only about 1% to 2% of bladder cancers are squamous cell carcinomas. Seen with a microscope, the cells look much like the flat cells that are found on the surface of the skin. Nearly all squamous cell carcinomas of the bladder are invasive.
Adenocarcinoma
Only about 1% of bladder cancers are adenocarcinomas. These cancer cells have a lot in common with gland-forming cells of colon cancers. Nearly all adenocarcinomas of the bladder are invasive.
Small cell carcinoma
Less than 1% of bladder cancers are small-cell carcinomas. They start in nerve-like cells called neuroendocrine cells. These cancers often grow quickly and usually need to be treated with chemotherapy like that used for small cell carcinoma of the lung.
Sarcoma
Sarcomas start in the muscle cells of the bladder, but they are very rare. More information can be found in Soft Tissue Sarcoma and Rhabdomyosarcoma.
These less common types of bladder cancer (other than sarcoma) are treated a lot like TCCs, especially early-stage tumors, but if chemotherapy is needed, different drugs might be used.
