Aromatase inhibitors (AIs) such as anastrozole have been used off-label for cases of gynecomastia occurring during puberty but are less effective than SERMs.A few cases of gynecomastia caused by the rare disorders aromatase excess syndrome and Peutz–Jeghers syndrome have responded to treatment with AIs such as anastrozole. Androgens/anabolic steroids may be effective for gynecomastia. Testosterone itself may not be suitable to treat gynecomastia as it can be aromatized into estradiol, but nonaromatizable androgens like topical androstanolone (dihydrotestosterone) can be useful. Surgery
If chronic gynecomastia does not respond to medical treatment, surgical removal of glandular breast tissue is usually required. The American Board of Cosmetic Surgery reports surgery is the "most effective known treatment for gynecomastia." Surgical treatment should be considered if the gynecomastia persists for more than 12 months, causes distress (ie physical discomfort or psychological distress), and is in the fibrotic stage. In adolescent males, it is recommended that surgery is postponed until puberty is completed (penile and testicular development should reach Tanner scale Stage V).Surgical approaches to the treatment of gynecomastia include subcutaneous mastectomy, liposuction-assisted mastectomy, laser-assisted liposuction, and laser-lipolysis without liposuction. Complications of mastectomy may include hematoma, surgical wound infection, breast asymmetry, changes in sensation in the breast, necrosis of the areola or nipple, seroma, noticeable or painful scars, and contour deformities. In 2019, 24,123 male patients underwent surgical treatment for gynecomastia in the United States, accounting for a 19% increase since 2000.
When surgery is performed, the gland is routinely sent to the lab to confirm the presence of gynecomastia and to check for tumors under a microscope. The utility of pathologic examination of breast tissue removed from male adolescent gynecomastia patients has recently been questioned due to the rarity of breast cancer in this population. Classification
The spectrum of gynecomastia severity has been categorized into a grading system:
Grade I: Minor enlargement, no skin excess
Grade II: Moderate enlargement, no skin excess
Grade III: Moderate enlargement, skin excess
Grade IV: Marked enlargement, skin excess

Treatment
Mild cases of gynecomastia in adolescence may be treated with advice on lifestyle habits such as proper diet and exercise with reassurance. In more severe cases, medical treatment may be offered including medication or surgical intervention. Medication
Gynecomastia can respond well to medical treatment although it is usually only effective when done within the first two years after the start of male breast enlargement. Selective estrogen receptor modulators (SERMs) such as tamoxifen, raloxifene, and clomifene may be beneficial in the treatment of gynecomastia but are not approved by the Food and Drug Administration for use in gynecomastia. Clomifene seems to be less effective than tamoxifen or raloxifene. Tamoxifen may be used to treat gynecomastia in adults and of the medical treatments used, tamoxifen is the most effective. Recent studies have shown that treatment with tamoxifen may represent a safe and effective mode of treatment in cases of cosmetically disturbing or painful gynecomastia.