A black hard lump on the leg is mostly considered to be melanoma, dermatofibroma, common warts, etc. After clarifying the cause of the disease, you can choose medication, surgical treatment, physical therapy and other ways. 1. Melanoma: Surgery is the first choice, and if metastasis has occurred, chemotherapy should be combined. 2. sebaceous fibroma: this disease usually does not need special treatment, such as suspected of malignant tendency, the need for timely surgical resection treatment. 3. common warts: caused by human papilloma infection, can take freezing, electrocautery, scraping and laser and other physical therapy, in order to remove warts; not suitable for physical therapy patients, can be used externally Vitamin A acid ointment, fluorouracil ointment drug treatment. It is recommended that the patient to the regular hospital dermatology, clear diagnosis, comply with the doctor’s instructions regular treatment, in the doctor’s guidance under the use of drugs, not blindly self-medication.