Melanoma is a malignant tumor that originates in certain types of cells in the skin. There are two main types of skin tumors: carcinoma and melanoma. Carcinomas (basal and squamous) are the most common. Melanomas are much less common, but its evolution may be the worst prognosis. It is more likely to invade nearby tissues and spread to other parts of the body than other types of skin cancer. Melanoma can also occur in the mucous membranes (moist thin layers of tissue that cover areas such as lips). It is curable, provided it is diagnosed early. It is essentially manifested by the appearance of a small pigmented area on healthy, or changing the size or color of a mole (nevus) skin. In this type of tumor, cells can break away from the place of origin, travel through the blood or lymphatic or capillaries vessels or stay in different organs (metastasis). Melanomas arise from melanocytes, cells that produce pigment (melanin) normal skin, in areas adjacent to a mole or directly on a pre-existing mole. Some people have an increased risk for melanoma: those with very white skin that always get red and never tan; those with numerous moles, atypical moles that have direct relatives and family members who have had melanoma.