Case report. An unusual case of precocious puberty.

An almost 3-year-old boy was evaluated for pubic hair and unilateral testicular enlargement 1 week after resection of an astrocytoma of the posterior fossa. Rather than the expected diagnosis of central precocity due to increased intracranial pressure, a diagnosis of congenital adrenal hyperplasia (21-hydroxylase deficiency) with testicular adrenal rest cells was made. The differential diagnosis, laboratory evaluation, and currently accepted medical management of congenital adrenal hyperplasia are described.