Melanoma Skin Cancer Facts
The skin is the largest organ of the body. The skin functions as a protective barrier that interfaces with a sometimes-hostile environment. It is also very involved in maintaining the proper temperature for the body to function well. It gathers sensory information from the environment, and plays an active role in the immune system protecting us from disease. There are 3 layers of skin - the epidermis, dermis, and subcutaneous tissue.
Skin cancer is the most common type of cancer in the United States. About one million Americans develop skin cancer each year. There are many types of skin cancer. Two of the most common types are basal cell cancer and squamous cell cancer. These are sometimes referred to as nonmelanoma skin cancers. This information is primarily about the most serious type of skin cancer, melanoma.
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Q & A with Emory Dermatologist Dr. Molly McCoppin
How Skin Cancer Develops
Skin cancer occurs when there is an uncontrollable growth of abnormal cells in a layer of the skin. There are three common forms of skin cancer that are distinguished by the types of cells affected - Melanoma, basal cell carcinoma, and squamous cell carcinoma.
What is melanoma?
The outer layer of skin, or the epidermis, is also made up of several layers. There are also several specialized cells in the epidermis. In the simplest terms, melanoma is a cancer of melanocytes, which are cells whose primary function is to make pigment. These are the same cells that make birthmarks and freckles; however in those cases the cells are not cancerous. Although most melanomas are dark or "pigmented", some melanomas are not. These are called "amelanotic melanomas" and with the exception of not having pigment, behave similarly to pigmented lesions. Melanocytes are also found in the eye and in mucosal surfaces such as the mouth and bowel which is why patients can develop melanoma there as well as on the skin.
Who is at risk for melanoma?
Caucasians have a risk of melanoma that is about ten times that of other racial and ethnic groups, but everyone has some risk. Risk is highest in people who have a high number of moles (more than 20-30 in an adult), who have strong family history of melanoma, and who tend to sunburn easily. If you are concerned about your risk discuss this with your primary care provider or dermatologist. In some cases it may be appropriate to visit the Dermatologists at Emory as part of your care, but you should start with your own primary care provider or dermatologist.
Other Types of Skin Cancer
Basal cell carcinoma is the most common form of skin cancer. This type of skin cancer does not typically spread, but does require treatment. Basal cell carcinomas most often develop in areas of the skin exposed to the sun.
Squamous cell carcinomas develop in the middle layer of the epidermis. This type of cancer can spread and can be life threatening if not treated appropriately.