Melanoma, the most serious form of skin cancer, is characterized by the uncontrolled growth of pigment-producing cells called melanocytes. Exposure to natural and artificial ultraviolet light, such as tanning beds, is a risk factor for developing melanoma, but genetics can also play a role. Melanoma can develop from an existing mole or can arise from normal-appearing skin. If melanoma is diagnosed early, it can be surgically removed and completely cured. However, if melanoma remains undetected and grows, it can spread to lymph nodes and other organs and can eventually lead to death. Advanced melanoma may require treatment such as chemotherapy, radiation, and immunotherapy.