[Gynecomastia in boys before puberty].

Gynecomastia is seldom observed in prepubertal boys. Sixteen cases are reported in this work, 3 of them being related to a defect of 11 hydroxylase with virilizing adrenal hyperplasia and 13 being considered as idiopathic. These gynecomastias consist of a slight breast enlargement, often unilateral (10 of 16) and may spontaneously disappear after 3 to 12 months (5 of 16 cases). In the so-called idiopathic cases, the hormonal investigations performed gave normal results, so that no physiopathological explanation could be suggested.