Types of bladder cancer

Nearly all cancers of the bladder start in the layer of cells which form the lining (urothelium) of the bladder. These are called transitional cell or urothelial cell cancers. They come in a very wide range of forms and can behave in very different ways. For example, they may occur as a small, wart-like growth on the inside of the bladder, which can be removed in a simple operation and may never come back. Sometimes they can form a large tumour which grows into the muscle wall of the bladder and needs major surgery.

read more at http://www.cancerbackup.org.uk/Cancertype/Bladder/General/Typesofbladdercancer