Generally, if a nevus is benign, it rarely becomes malignant even if it is incompletely removed. If the nevus is malignant, it may become malignant if the excision is incomplete. If the excision is incomplete, it will seldom lead to malignant transformation. After the operation, the patient should take good care of the mole, in general, if the patient often rubs it and stimulates it again and again, it may increase the chance of cancerous transformation. If the pigmented nevus itself belongs to malignant melanoma, if the diseased tissue is not completely removed during the surgery, the remaining part of the nevus may undergo malignant transformation, which will have a greater impact on the patient’s body. After the surgery, these patients often have symptoms such as itching and ulcers at the surgery site. Patients who need to remove the pigmented nevus should choose regular hospitals for treatment, and after the removal of the pigmented nevus, patients need to pay attention to the protection of the wound to avoid local infection.