The Hypertrophy of the Male Breast

GYNECOMASTIA, hypertrophy of the male breast, has been extensively described in the literature of the last century. However, its etiology has been shrouded in mystery and all the hypotheses concerning it have been of a purely speculative nature. It was only with the progress in endocrinology that a rational basis was established for investigation of this condition. Studies of the sex hormones have revealed that the male and female sex hormones are closely related and that both are present in either sex. The influence of the sex hormones on the normal and pathological development of different organs, particularly of the breast, has been established. The mutual relationship between the sex glands and those controlling metabolism and growth has been noted. It was this knowledge of hormonal activity that stimulated experimental studies of gynecomastia which have brought us closer to a real understanding of its etiology.