Gynecomastia (GYN), also known as gynecomastia or male gynecomastia, is a common benign disease of the male breast with an incidence of 32%-65% in the male population and can be found in 40%-55% of male autopsies. The main symptom is a painful swelling behind the areola. There are various causes of gynecomastia, which can be classified as physiologic, pathologic, idiopathic and pharmacologic. Physiologic gynecomastia can be seen in newborns, adolescent males, and older males. Pathological gynecomastia can be seen in patients with testicular insufficiency or hypotension, patients with liver disease with hormone inactivation disorders, and patients with prostate disease treated with estrogen; it can also be seen in patients with Kallman syndrome, hypopituitary hypofunction, hypothalamic, pituitary or pineal tumors, hyper- or hypothyroidism, chronic malnutrition, long-term use of certain drugs, and certain tumors. A variety of drugs can lead to male breast development, including omeprazole, cimetidine, captopril, isoniazid, and ambrisentin. Indications for surgery: 1. Breast diameter of 4 cm or more, not receding for more than 1 year; 2. Obvious enlargement of the breast, affecting the aesthetics; 3. Ineffective drug treatment; 4. Symptomatic; 5. Suspected cancer. The surgical methods for gynecomastia can be broadly divided into three types: fat aspiration, sharp excision and fat aspiration combined with sharp excision. 1. Simple fat aspiration is suitable for patients with mainly fatty hyperplasia, and the small amount of remaining breast tissue will not affect the shape of the breast. 2.For patients with mainly parenchymal hyperplasia, the hyperplastic breast parenchyma is difficult to be removed by suction tube, so only sharp excision surgery can be used. The traditional procedure is to make a large incision in the upper or lower outer crease of the hyperplastic breast and remove the hyperplastic breast tissue after freeing the flap, which often retains more deep breast tissue and is more traumatic, with more bleeding, high recurrence rate, high infection rate, poor appearance and poor results. For patients with both more fatty tissue and more substantial glands, fat aspiration combined with transareolar incision excision can be used. In recent years, the application of lumpectomy technology has provided new treatment means for the surgical treatment of gynecomastia. In our department, there are several cases of subcutaneous mastectomy under breast lumpectomy with good postoperative recovery, which is less traumatic, with small surgical scar and can avoid damage to blood vessels and nerves.