Types of bladder cancer
The most common type is transitional-cell cancer, also known as urothelial carcinoma. This type of cancer begins in the cells of the lining of the bladder (urothelium) and can be invasive or noninvasive.
In noninvasive cancer of the bladder, the cancer cells are located only in the internal lining of the bladder and have not spread to the muscle layer.
Noninvasive bladder cancer may appear in different forms. Papillary tumors typically grow in a shape resembling fungus on the lining of the bladder.
Carcinoma in situ (CIS) usually manifests as flat red spots on the lining of the bladder. It can be quick to grow and, if not treated, there is a high risk of it becoming an invasive cancer.
Rarer types of bladder cancer include squamous-cell cancer and adenocarcinoma. These are generally invasive.