• We report the clinical and hormonal findings in two boys with isosexual precocity secondary to Leydig cell tumor of the testis. The hormonal profile at the initial evaluation was quite different in the two cases suggesting differences in steroid biosynthesis by the tumors. These differences indicate that a dexamethasone suppression test may be required to differentiate between Leydig cell tumors and congenital virilizing adrenal hyperplasia with adrenal rest tissue located within the testes.
(Am J Dis Child 132:494-497, 1978)