Precocity of sexual development, while constituting a relatively small problem in clinical practice, is nevertheless intriguing from the viewpoint of its etiology and pathogenesis. One of us1 has emphasized that, while it is usually recognized that hypergenitalism may result from hypergonadism, hyperplasia or tumorous formation of the adrenal cortex and may be associated with pineal tumors in boys, it is little realized that lesions in the brain without involvement of the pineal gland, and particularly without involvement of the hypothalamus, may produce sexual precocity.
Although the mechanism for this remains conjectural, the appreciation that precocious sexuality may be associated with hypothalamic lesions without gross changes in the known endocrine glands and without recognizable evidence of intracranial disease is important.
We studied the case of a 22 month old girl exhibiting precocious sexuality, in whom necropsy revealed what was interpreted as an ectopia of brain tissue between the infundibulum and