Melanoma, the most serious type of skin cancer, develops in the cells (melanocytes) that produce melanin - the pigment that gives your skin its color. Melanoma can also form in your eyes and, rarely, inside your body, such as your nose or throat. The exact cause of all melanomas is unclear, but exposure to ultraviolet (UV) rays from the sun or tanning lamps and beds increases your risk of developing melanoma. Limiting your exposure to UV rays can help reduce your risk of melanoma. The risk of melanoma appears to increase in people under 40, especially women. Knowing the warning signs of skin cancer can help ensure that cancerous changes are detected and treated before the cancer spreads. Melanoma can be diagnosed early if it is detected early.

When Melanoma Survives Something is Wrong with the Melanin-producing Cells (Melanocytes) That Give Your Skin. Normally, skin cells grow in a controlled and orderly fashion - pushing healthy cells to the surface of your skin, where they die and eventually fall off. But when certain cells develop DNA damage, new cells can start to grow in an uncontrolled fashion and can form a mass of cancer cells. It is not clear what damages DNA in skin cells and how it leads to melanoma. A combination of factors, including environmental and genetic factors, is likely to cause melanoma.