The patient was a 40-year-old woman who was admitted to the hospital with “a left breast lump found for 4 months”. The examination showed “a 2.5 cm long hard mass near the edge of the lateral quadrant of the left breast with a poorly smooth surface and poor mobility”. On 2010-7-15, a radical mastectomy for left breast cancer (axillary lymph node dissection under lumpectomy) was performed under general anesthesia at noon. A biopsy of the breast mass was first performed under local anesthesia, and the frozen pathology showed “breast cancer”, so radical breast-conserving surgery was performed: the breast tissue at the edge of the original tumor was further excised, and no cancer residue was found by sending it for frozen examination. The left axilla was injected with 450 ml of lipolysis solution (NS 250 ml + dH2O 250 ml + 5% NaHCO3 10 ml + 2% lidocaine 10 ml + epinephrine 0.5 mg), and after 10 minutes, liposuction was performed with a No. 6 uterine aspirator, and a total of about 250 ml of broken fat was aspirated. Incisions of 1 cm, 0.5 cm and 0.5 cm were made at the flat nipple in the left axillary midline, the outer edge of the left pectoralis major muscle and the anterior edge of the left latissimus dorsi muscle, respectively, and the corresponding Trocar was placed, and lumpectomy, separating forceps and electric scissors were introduced. The lymph nodes in the axilla were removed, and the lymph nodes and fat attached to the vascular nerve interval were removed. The lymph nodes in the lateral group of the axillary vein and the subscapular group of lymph nodes were cleared, and the subscapular vessels and the thoracic dorsal nerve and vessels were preserved. Next, the lymph nodes of the anterior external group of the pectoralis major muscle were cleared along the outer edge of the pectoralis major muscle, and the fatty lymph tissue and Rotter’s lymph nodes of the interstitial muscle were cleared by entering the interstitial space of the pectoralis major and minor muscles. The cleared adipose lymphatic tissue was removed, and the field was rinsed and soaked with 1500 ml of warm distilled water and checked for bleeding. The patient’s vital signs were stable during the operation, and he returned to the ward after waking up. After the operation, the patient recovered well and quickly and was discharged as scheduled. Postoperative pathology: adenocarcinoma of the left breast duct and 1/12 metastasis of axillary lymph nodes. In this case, when breast-conserving surgery requires axillary lymph node dissection, choosing lumpectomy will not only be minimally invasive, but also have smaller local wound and better cosmetic effect.