Cancer is when cells in the body change and grow out of control. To help you understand what happens when you have cancer, let's look at how your body works normally. Your body is made up of tiny building blocks called cells. Normal cells grow when your body needs them and die when your body does not need them any longer.

Cancer is made up of abnormal cells that grow even though your body doesn't need them. In most cancers, the abnormal cells grow to form a lump or mass called a tumor. If cancer cells are in the body long enough, they can grow into (invade) nearby areas. They can even spread to other parts of the body (metastasis).

Urethral cancer is a very rare type of cancer that starts in the urethra. This is the tube that carries urine out of your body. 

There are 3 types of urethral cancer:

• Squamous cell carcinoma starts in the cells that line the inside of the urethra. In women, it starts in the part of the urethra near the opening of the urethra closest to the outside of the body.

• Adenocarcinoma starts in the glands near the urethra.

• Transitional cell carcinoma starts in the cells of the urethra closest to the bladder neck.

The urethra is a tube that carries urine from the bladder to the outside of the body. In women, the urethra is about 1-1/2 inches long. It reaches from the bladder to an opening above the vagina. In men, the urethra is about 8 inches long. It passes through the prostate and the penis to an opening on the glans, or the tip of the penis.

If you have questions about urethral cancer, talk with your healthcare provider. He or she can help you understand more about this cancer.