Malignant melanoma is a highly malignant skin cancer, occurs in the skin surface, accounting for 20% of skin cancer. International surveys of its total incidence rate of 1% -3% of malignant tumors. The white race malignant melanoma; the highest incidence, morbidity, Queensland, Australia as high as 28.4/10 whites million, the incidence of malignant melanoma; the other was 0.8/10 million. In recent years, many countries, the incidence of malignant melanoma of the skin in the rapid growth rate, the corresponding mortality rates are increasing, early age of onset and more and more, so be it seriously.
Cutaneous malignant melanoma is derived from normal skin melanocytes, or swelling of the liver cancer cells, mainly in elderly men and women the incidence of malignant melanoma per significant. Parts of the overall distribution of the incidence of head and neck, trunk, each limb about 25%, upper limb (including subungual malignant melanoma) accounts for about 12.5%, 12.5% other sites. In different sexes, very different parts of the distribution, men who have malignant melanoma in the trunk about 50%, and about 50% of digital malignant melanoma on the limbs, especially legs majority. And racial predilection is also closely related to malignant melanoma in the black on the lower limbs of more than 60%, and lesions have occurred in the bottom half of the patients.