Melanoma, also known as malignant melanoma, is a cancer that develops from pigment cells called melanocytes. It is commonly occurred in the skin, also in the mucosa, eye choroid and other parts. In Asians and some other people, the primary melanoma in the skin accounts for 50% to 70%, and the acral melanoma is most common (about 50% of all melanoma), that is, occurring in foot, toes, finger end and a lower part of the site, followed by mucosal melanoma (about 20%), while in the European and white, subspecies of these two subtypes only account for 5% of all melanoma. Melanoma is the dangerous type of skin cancer, and is prone to distant metastasis. Early diagnosis and treatment are particularly important.