McCune-Albright syndrome in a male child: a clinical and endocrinologic enigma.

A 6 5/12-year-old boy with polyostotic fibrous dysplasia, café-au-lait pigmentation of the skin, and precocious pubertal development was studied for two years. Parathormone, calcium, phosphorus, testosterone, cortisol, and growth hormone levels were within normal limits. Urinary 17-ketosteroids, 17-ketogenic steroids, and estrogens were at the upper limits of normal. After GnRH stimulation, there was only a very slight increase in LH and no increase in FSH. There was no increase in TSH after TRH, and plasma levels of T4 and T3 were normal. The plasma prolactin level was within normal limits, and increased after TRH stimulation (with a second, delayed upsurge). Abnormal distribution of 131I in the thyroid was evident, without clearcut evidence of hyperfunctioning areas after TSH stimulation and T3 suppression tests followed by conventional scanning and gamma camera scintiphotography. Our findings do not support the claimed, single, hypothalamic origin of the disease that is presumed to result in overproduction of releasing hormones; they are more in keeping with a pleiotropic, scattered peripheral lesion, possibly of embryonal origin.