[Gynecomastia].

The development of excess breast tissue in the male, known as gynecomastia, is a common finding seen by physicians. It is a source of embarrassment to the adolescent and of surprise and concern to the older male. The main challenge to the physician lies in separating the patients with gynecomastia as a symptom of a serious underlying disease, requiring specific treatment, from the vast majority of individuals with gynecomastia, in whom there is no underlying pathology. Numerous pathogenic mechanisms have been involved in the genesis of gynecomastia, leading all to an increased net estrogen/androgen ratio that effectively acts at the target tissue (breast). Special emphasis must be done in puberal gynecomastia since 50 to 75% of boys in these developments phase have a breast enlargement. In the present paper we provide an overall review of hormonal pathogenesis and diagnostic clues, as well as current therapeutic guidelines regarding gynecomastia.