Breast 4A nodule, if benign, the surgery usually takes about 1 hour to do; if malignant, it usually takes about 2 to 2.5 hours, which needs to be determined according to whether the nodule is benign or malignant, and cannot be generalized. Breast nodules are a common breast disease, the cause of which is still unclear. It may be related to factors such as endocrine hormone level disruption or gene mutation, and often manifests itself as a hard lump on one or both sides of the breast. If ultrasonography is performed and suggests that the breast nodule is category 4A, surgery is usually required. 1. Benign nodule: If the ultrasound classification of breast nodule is 4A, most of them are benign tumors, and frozen pathological examination is usually performed after removing the breast nodule and part of the breast gland with local anesthesia. Usually the operation time is 20-30 minutes and the frozen pathology examination time is 30-40 minutes, which takes about 1 hour in total. 2. Malignant nodule: If the intraoperative frozen pathology result suggests that the breast nodule is malignant, i.e. breast cancer, it is usually necessary to change the anesthesia mode to general anesthesia, and then continue to perform the modified radical mastectomy for breast cancer, which will take about 1 to 1.5 hours of operation time and a total of 2 to 2.5 hours. After the operation, the need for adjuvant treatment such as radiotherapy will be decided based on the results of the pathology examination. Patients suffering from breast 4a nodules are advised to follow the doctor’s instructions for prompt treatment.