[Skip to Content]
[Skip to Content Landing]
June 10, 1974


JAMA. 1974;228(11):1423. doi:10.1001/jama.1974.03230360053029

At two periods in male life, enlargement of breast tissue (gynecomastia) may occur "normally"—at birth and at puberty. Whereas gynecomastia at birth is attributed to transplacental issuance of estrogens, the cause at puberty is unknown. The great majority of pubescent boys show enlargement of one or both breasts, usually at a time when they are undergoing rapid virilization. The swollen breasts are tender and rarely grow so large as to necessitate amputation for cosmetic or psychological reasons; usually the swelling is slight and disappears spontaneously.

Although prepuberal breast enlargement in girls (premature thelarche) is relatively common and of itself has no importance, prepuberal gynecomastia in boys is rare. Latorre and Kenny1 recently reported that during a tenyear period, they observed 50 instances of premature thelarche and seven cases of prepuberal gynecomastia. In all seven boys, estrogen production by a testicular or an adrenal neoplasm was carefully excluded by appropriate