Combined treatment with bicalutamide and anastrozole in a young boy with peripheral precocious puberty due to McCune-Albright Syndrome.

McCune-Albright Syndrome (MAS) is a congenital endocrine disorder due to mosaic tissutal hyper-function. We describe a boy with a molecularly confirmed MAS, clinically evident with congenital café-au-lait spots, bone fibrous dysplasia, hyperthyroidism, and renal phosphate wasting syndrome. At 4.6 years of age he disclosed a rapid progression of peripheral puberty, so we decided to treat him with bicalutamide 25 mg/day and anastrozole 1 mg/day. Combined third generation aromatase inhibitors - competitive androgen receptor blockers were employed in familial male precocious puberty (FMPP). Combined treatment was performed for 49 months from the age of 4.6 to 6.7 years. The patient underwent clinical, laboratory, and instrumental evaluation twice a year from the first admission to the current age. This treatment caused a rapid normalization of growth velocity, subsequent reduction of penile androgenization, and stabilization of testicular volume. The therapy was well tolerated for all its duration and neither side effects, nor secondary hypothalamic activation were noted. This report provides further evidence of effectiveness and safety of combined third generation aromatase inhibitors - competitive androgen receptor blockers in male precocious peripheral puberty, firstly employed in male MAS, and contributes to expand the spectrum of disorders in which their employment may reveal promising.