A giant ovarian cyst in a neonate with classical 21-hydroxylase deficiency with very high testosterone levels demonstrating a high-dose hook effect

Congenital adrenal hyperplasia (cah) is a group of disorders affecting the adrenal steroid synthesis. the most common form,21-hydroxylase deficiency (21-ohd),leads to decreased production of cortisol and aldosterone with increased androgen secretion. in classic cah,glucocorticoid treatment can be life-saving and serves to bring the symptoms under control. however,the treatment challenge is to effectively control the excess androgen effect by using the lowest possible glucocorticoid dose. previous studies suggested a relationship between ovarian cyst formation and adrenal androgen excess,but neonatal large ovarian cysts have been very rarely reported in newborns with cah. here,we present the unique case of a neonate with classical 21-ohd who underwent surgery for a giant (10×8×7 cm) unilateral solitary ovarian follicular cyst on the 2nd postnatal day. hormonal evaluation of the patient revealed high-dose hook effect for serum testosterone levels for the first time by a two-site immunoradiometric assay. possible mechanisms by which androgen excess may cause ovarian cyst formation are discussed. ©journal of clinical research in pediatric endocrinology.