Isosexual precocious pseudopuberty secondary to a feminizing adrenal tumor.

We report a 2 10/12-yr-old girl with precocious pseudopuberty due to a feminizing adrenal carcinoma without Cushing's syndrome. The patient had marked elevation of plasma concentrations of the delta 5 adrenal steroids dehydroepiandosterone and dehydroepiandrosterone sulfate and increased levels of androstenedione, estrone, estradiol, and testosterone. Adrenal microsomal 3 beta-hydroxysteroid dehydrogenase-isomerase 17-hydroxylase, 17,20-desmolase, and 21-hydroxylase activities in the tumor and adjacent normal adrenal gland were measured. The tumor had approximately normal levels of 17-hydroxylase and 17,20-desmolase activity, with low levels of 21-hydroxylase and 3 beta-hydroxysteroid dehydrogenase-isomerase activities. This combination of enzyme activity may explain the absence of Cushing's syndrome and the high levels of delta 5 adrenal steroids. This patient demonstrates that adrenal neoplasms arising in girls may mimic isosexual true precocious puberty and should be included in the differential diagnosis of precocious puberty.