Symptoms of malignant nevus of melanoma include changes in the shape and color of the nevus, which are mostly accompanied by itching, pain, as well as crusting and breaking. If a nevus is malignant, the shape of the nevus may change, the overall shape is irregular and asymmetric, and the area or volume increases rapidly within a short period of time; secondly, the color of the nevus may also change, and the overall color is not uniform; moreover, multiple similar small nevi, i.e. satellite nevus, appear around the original nevus; local nevus with malignant transformation may also be accompanied by itching, pain, vesiculation, ulceration, bleeding, scabs, and other conditions. It may also be accompanied by itching, pain, ulceration, bleeding and scabs when the localized nevus becomes malignant. If the above symptoms appear, consider the possibility of malignant nevus, and suggest the patient to consult a professional doctor for standardized diagnosis and treatment in time.