thumb|231x231px|Cross-section of the male genitourinary system showing a cancer within the bladder. When a cancer occurs it is most likely to be a transitional cell carcinoma. Cancer of the bladder is known as bladder cancer. It is usually due to cancer of the urothelium, the cells that line the surface of the bladder. Bladder cancer is more common after the age of 40, and more common in men than women; other risk factors include smoking and exposure to dyes such as aromatic amines and aldehydes. When cancer is present, the most common symptom in an affected person is blood in the urine; a physical medical examination may be otherwise normal, except in late disease. Bladder cancer is most often due to cancer of the cells lining the ureter, called transitional cell carcinoma, although it can more rarely occur as a squamous cell carcinoma if the type of cells lining the urethra have changed due to chronic inflammation, such as due to stones or schistosomiasis.
thumb|231x231px|cross-section of the male genitourinary system showing a cancer within the bladder when a cancer occurs it is most likely to be a transitional cell carcinoma cancer of the bladder is known as bladder cancer it is usually due to cancer of the urothelium the cells that line the surface of the bladder bladder cancer is more common after the age of 40 and more common in men than women; other risk factors include smoking and exposure to dyes such as aromatic amines and aldehydes when cancer is present the most common symptom in an affected person is blood in the urine; a physical medical examination may be otherwise normal except in late disease bladder cancer is most often due to cancer of the cells lining the ureter called transitional cell carcinoma although it can more rarely occur as a squamous cell carcinoma if the type of cells lining the urethra have changed due to chronic inflammation such as due to stones or schistosomiasis