Partial benefit of anastrozole in the long-term treatment of precocious puberty in McCune-Albright syndrome

We report a long-term follow-up on the use of anastrozole in the treatment of peripheral precocious puberty (PP) in McCune-Albright syndrome (MAS). A girl, age 3 years and 9 months, was diagnosed with MAS due to PP, café-au-lait spots, and polyostotic fibrous dysplasia. Serum estradiol was elevated, and gonadotropins were suppressed. Pelvic ultrasound showed an enlarged uterus and a follicle cyst (13 mm) in the left ovary. Bone scintigraphy showed osteogenic lesions on the skull, humerus, tibia, and acetabulum. Bone age was 3 years and 5 months at the chronological age of 3 years. After 36 months of treatment with anastrozole (1 mg/day), there was suppression of breast growth, normalization of growth velocity and serum estradiol, and disappearance of ovarian cysts. However, there was increase in uterine volume, advancement of bone age, and two episodes of vaginal bleeding (18th and 24th months). This report shows the partial benefit of anastrozole in the treatment of peripheral PP of girls with MAS.