What is Skin Cancer?

A cancer that forms in someone's skin is generally referred to as skin cancer, though there are many different varieties. According to the National Cancer Institute, skin cancer is the most common form of cancer in the United States. Almost one million Americans develop skin cancer each year.

During the normal course of time, skin cells grow old and die and are replaced by new skin cells. Sometimes this process goes awry and old cells do not die when they should or new cells are created when they are not needed. These extra cells form a mass called a tumor. When cancer forms in a cell that makes pigment it is called melanoma. If it forms in a cell that does not make pigment and makes up the surface of the skin it is called non-melanoma skin cancer.

Types of Skin Cancer

Basal and Squamous Cell (Non-Melanoma)
Basal and squamous cell are the two most common forms of skin cancer and are sometimes grouped together as non-melanoma skin cancer. If a cancerous growth forms in the small, round cells that form the surface of the skin it is called basal cell skin cancer. If it forms in the flat cells that make up the surface of the skin it is called squamous cell skin cancer.

Basal cell skin cancer grows slowly and usually occurs on the areas of the skin that have been exposed to sunlight over a long period of time, such as the face. Basal cell skin cancer does not usually spread to other areas of the body.

Squamous cell skin cancer can be in parts of the skin that have been exposed to sun and in areas that have not. Very rarely, the cancer can spread to the lymph nodes and other areas of the body.

In 2008, The American Cancer Society expects more than one million basal and squamous cell skin cancers to be diagnosed in the United States.

Melanoma
The most dangerous form of skin cancer is melanoma, which grows in skin cells that make pigment. Melanoma is dangerous because it can spread to other parts of the body. However, it can be treated and cured if caught early. The American Cancer Society estimated there will be more than 62,000 new cases of melanoma, resulting in more than 8,400 fatalities, in the United States in 2008.