Melanoma is a kind of skin tumor disease with high malignant degree caused by cancerous transformation of melanocytes. It is represented by rapid malignant transformation of original nevus in a short period of time and sudden appearance of large discoloration on the skin, with poor prognosis, and it should be treated actively under the guidance of doctor after diagnosis. The cause of melanoma is still unclear, and it is mostly found in people with fair skin, people with long time sun exposure, people with multiple moles or dysplastic moles, and people with family history of melanoma are more prone to it. There are also other factors that make people susceptible to melanoma, such as viral infections, ionizing radiation or trauma. Melanin tumors are more prevalent in people between the ages of 50-55 and are more prevalent in men than in women, and more prevalent in Caucasians than in Yellows. Melanin tumors mostly occur in the skin or mucous membranes, such as the soles of the feet, the end of the fingers and under the nails, as well as the eyes, nasal cavity, oral cavity, digestive mucous membranes and so on. It is often manifested as rapid enlargement and elevation of the original mole, which may be nodular or cauliflower-like, with changes in character or color, or even itching and bleeding, accompanied by a halo of pigmentation around it. It may also be accompanied by other symptoms depending on the site of disease, such as eye melanoma will be accompanied by mosquito, vision loss, pupil shape change, etc. Melanoma is easy to metastasize to various tissues of the body through lymph nodes and blood, with faster progress and higher degree of malignancy. And according to the different parts of metastasis, it can show different clinical symptoms, such as bone metastasis can show body pain, lung metastasis can show cough, hemoptysis symptoms. Generally speaking, the clinical diagnosis can be confirmed through pathological and histological examination, and surgical resection is required for treatment. Early diagnosis and treatment of melanoma is of great significance, therefore, once you find the above abnormalities in your skin, please consult the doctor in time.