Most melanomas on the bottom of the foot refer to malignant melanoma. In the early stage, it may show a localized black swelling, usually more common in the heel, with no obvious pain or other discomfort, but it may also be accompanied by an ulcer that does not heal over time. In such cases, further extended surgical excision is required, and then postoperative pathology can determine the nature. For malignant melanoma is a highly malignant and prone to early hematogenous and lymphatic metastases. Malignant melanoma is prone to lung metastasis and inguinal lymph node metastasis. Generally a comprehensive examination, such as PET-CT, is also needed to find out if there are any other local lesions. In general, malignant melanoma is not too sensitive to chemotherapy. Immunotherapy can be applied, such as the application of interferon, interleukin, etc. There is also the possibility of adjuvant chemotherapy with dacarbazine, in addition, you can also try to apply targeted drug therapy.