Cancer is caused when a group of unhealthy cells or damaged DNA doesn't die but instead begins growing out of control. These cancer cells begin interfering with normal cells, as they grow into other cells and continuously multiply. When these cancer cells form in the epidermis of the skin, in the melanocytes, it is known as melanoma skin cancer (Society, 2012). .
Melanoma is easier understood with the knowledge of the normal structure and function of the skin. Normal skin helps to protect all of the major organs in the body and is the largest organ of the body. The skin has three layers called the epidermis, the dermis, and the sub-cutis. The epidermis is the very thin, top layer of skin, at an average of 1/100 of an inch thick. The epidermis also contains quickly growing and dying keratinocytes, which are an important protein that helps the skin protect the rest of the body. "Melanocytes, the cells that can become melanoma, are also found in the epidermis." "These skin cells make a brown pigment called melanin, which gives the skin its tan or brown color" (Melanoma Skin Cancer, 2013). The skin is protected by melanin, which can be damaged from the harmful rays of the sun, and can penetrate the deeper layers of skin.
According to the American Cancer Society, "The epidermis is separated from the deeper layers of skin by the basement membrane (Society, 2012)." The basement membrane can become cancerous if skin cancer becomes more advanced then grows into the deeper layers of skin. The middle layer of skin is the dermis, which is much thicker than the epidermis. "The dermis contains hair follicles, sweat glands, blood vessels, and nerves that are held in place by a protein called collagen, which gives skin its elasticity and strength" (Melanoma Skin Cancer, 2013). The third and deepest layer of skin is the lowest part of the dermis that forms a network of collagen and fat cells, called the subcutis.