Testis tumors associated with congenital adrenal hyperplasia: a continuing diagnostic and therapeutic dilemma.

A 9-year-old boy with documented congenital adrenal hyperplasia owing to a deficiency in C21 hydroxylation is described. Precocious virilization and testicular asymmetry were noted when he was 5 years old. Both of these conditions persisted despite progressively larger doses of replacement steroid therapy. The right testis was 3 times larger than the left testis and serum testosterone was well within the adult male range. A right inguinal orchiectomy was performed. Pathologic diagnosis was interstitial cell tumor. A review of the literature emphasizes the continuing dilemma of separating interstitial cell tumors from hypertrophy of adrenal rest tissue in the presence of congenital adrenal hyperplasia. Possible methods of distinction are discussed.