Like many cancers, skin cancers -- including melanoma, basal cell carcinoma, and squamous cell carcinoma -- start as precancerous lesions. This WebMD slideshow tells you how to spot the early warning signs of skin cancer and seek treatment.
Melanoma:Melanoma is a cancer that develops in melanocytes, the pigment cells present in the skin. It can be more serious than the other forms of skin cancer because it may spread to other parts of the body (metastasize) and cause serious illness and death. About 50,000 new cases of melanoma are diagnosed in the United States every year.