Male breasts that develop female-like on one or both sides and have an enlarged appearance and protrude from the chest are suspected of being pseudo-feminine. This brings embarrassment when swimming, bathing and wearing a single garment. This is called gynecomastia. Gynecomastia occurs mostly during puberty and is still a normal condition. It may be caused by endocrine disorders. Gynecomastia differs histologically from gynecomastia in that there are no glandular lobes, only enlargement of the milk ducts, fibrous and fatty tissues, and cystic enlargement of the breast. Most of the surgically excised specimens were found to have fat and a small amount of white breast tissue. The largest breast specimens in this group were about 10 cm in diameter. Gynecomastia is generally divided into two categories: primary, which is common in adolescent and older male patients; and secondary, which is often secondary to certain diseases. For example, male hypogonadism, impaired liver function, etc. For adolescent breast enlargement, there is no need to rush to surgical treatment. Usually after 1 to 2 years, they can gradually shrink and return to normal. If you are around 25 years old and still have larger breasts, surgery is usually required.