Growth and pubertal outcome of three-years medical treatment of peripheral precocious puberty in a boy with McCune-Albright Syndrome: a case report

Peripheral precocious puberty (PPP) is an endocrine disorder characterized by premature, autonomous gonadal or extragonadal sexual steroid secretion. Accounting for about 20% of cases of precocious puberty, PPP is usually caused by rare diseases, including congenital adrenal hyperplasias, hormone-secreting gonadal and adrenal tumours, and McCune-Albright Syndrome (MAS). MAS is a rare, genetic disorder, mainly characterized by bone dysplasia, skin hyperpigmentation, and endocrine, hyperfunctioning disorders, including, as reported, PPP. Being a rare disease, PPP management in MAS patients is currently anecdotically reported, and no systematic approach is granted. A four years and two months boy was admitted in our department due to precocious pubarche and recent growth acceleration. At physical examination, he showed cafè-au-lait skin macules on thorax, abdomen, and posterior neck, and at hormonal evaluation he showed evidence of PPP, confirmed at both baseline and stimulated gonadotropin and testosterone levels. Due to the clinical features, he was diagnosed with MAS, that was further confirmed by the evidence of bone skull and testicular lesions; a thyroid lesion was also reported, but its relationship with MAS was questioned. He therefore started combined treatment with androgen receptor blocker bicalutamide and aromatase inhibitor anastrazole, that were able to significantly reduce growth acceleration and to stop pubertal progression. He safely continued combined treatment for three years, showing good efficacy on growth and pubertal outcome. Combined treatment with bicalutamide and anastrozole is a safe and effective long-term therapeutic approach to PPP in MAS boys, although evidences on its use are scarce; therefore, wider studies including larger populations deriving from different centres should be performed to obtain general consensus.