Until puberty the male and female breasts are identical.
Prepubertal breasts are composed of fibrofatty tissue and ducts lined by a single layer of epithelial cells with an underlying layer of myo-epithelium.
During puberty testosterone levels rise and cause involution and atrophy of the ducts.
The normal adult male breast is primarily composed of subcutaneous fat, stromal elements, a small nipple-areolar complex, and a pooly developed ductal system that ends blindly.
In the normal adult male breast terminal duct lobular units are rare and Cooper ligaments are absent.
In the female breast ducts, stroma, and glandular tissue predominate.
Normal male breasts appear homogeneous, are radiolucemt and have a prominent pectoralis muscle posteriorly, as seen on mammograms.
On ultrasound examination the anatomy of the normal male breast consists mainly of subcutaneous fat and skin.
Breast symptoms in male patients include a palpable lump, tenderness, and enlargement.