Skin cancer is a disease in which cancer cells grow in the skin.
The two most common kinds of skin cancer are:
- Basal cell carcinoma
—a slow-growing cancer that begins in the inner part of the outer layer of the skin; rarely spreads to other parts of the body
- It accounts for more than 90% of all skin cancers in the United States.
- Squamous cell carcinoma
—a cancer that starts in the outer layer of the skin
- It rarely spreads, but does so more often than basal cell carcinoma.
Basal Cell Carcinoma
© 2009 Nucleus Medical Media, Inc.
Cancer occurs when cells in the body (in this case, skin cells) divide without control or order. Normally, cells divide in a regulated manner. If cells keep dividing uncontrollably when new cells are not needed, a mass of tissue forms, called a growth or tumor. The term cancer refers to malignant tumors, which can invade nearby tissues and spread to other parts of the body. A benign tumor is unable to invade or spread.
It is important that skin cancers be found and treated early because they can invade and destroy nearby tissue. Another type of cancer that occurs in the skin is
There are also rare forms of skin cancer such as merkel cell carcinoma, sebaceous carcinoma, and eccrine carcinoma.