Letrozole Treatment in Idiopathic Peripheral Precocious Puberty Without Diagnosis of McCune-Albright Syndrome: A Case Report

Background: Peripheral precocious puberty (PPP) results from estrogen excess independent of gonadotropin activation. In cases of ovarian activation, McCune-Albright syndrome (MAS) and autonomous functional ovarian cysts should be considered. In the latter condition, clear evidence-based management guidelines are currently lacking. Case: A girl with PPP presented with premature thelarche, recurrent vaginal bleeding and elevated estradiol with ultrasound detection of ovarian cysts. MAS was excluded by clinical, radiological and genetic evaluation. Progressive pubertal development, recurrent bleeding, and advanced bone age led to initiation of off-label letrozole. Results: We reported a regression of uterine maturation and ovarian cyst, a normalization of blood tests and a cessation of vaginal bleeding, without adverse effects. Conclusions: Letrozole may represent an effective therapeutic option for non-MAS PPP.