A nodule or lump in the breast 4A, which has been clearly diagnosed as malignant, should undergo aggressive preoperative examination and preparation and be treated surgically by a deadline. The traditional surgical procedure is a modified radical mastectomy, which involves removal of the affected breast and lymph node dissection in the corresponding area. After surgery, regular dressing changes are necessary because the invasion is large and the postoperative period is prone to complications such as subcutaneous effusion. Postoperative treatment options also need to be selected in conjunction with detailed pathological staging, lymph node metastasis, and relevant results of immunohistochemistry. For malignant tumors, many patients need adjuvant intravenous chemotherapy, as well as local radiation therapy, and even long-term endocrine therapy after surgery, and the purpose of these treatments is mainly to reduce the chance of recurrence after surgery and prolong the survival time of patients.