ESPE Abstracts

Introduction: McCune - Albright syndrome is rare genetic disorder characterized by periphereal precocious puberty, fibrous bone dysplasia and cafe au lait skin spots.

Case: Almost 5 years old girl was sent to Endocrinological department due to precocious thelarche and menarche. At the time of first examination, patient had breast M 3 and large cafe au lait macule on the right tight, no pubic and axilar hair was present, no visible skeletal deformities were seen. Laboratory tests revelaled low gonadotropins and high estrogens levels, pubertal IGF 1 concentration and euthyroid condition. Her bone age was advanced. Pelvic ultrasonography showed bilateral ovarian follicles, hypophysis hyperplasia was confirmed on MRI scan. Due to advanced pubertal signs in order to reduce estrogen activity she was given LH RH agonists treatment while we were waiting for results of genetic analysis. Afetr short period of breast size regression and vaginal bleeding suppression under LH RH agonists administration both symptoms (vaginal bleeding and thelarche enlargement) occured again. Laboratory tests confirmed not only basal but also stimulated (LH RH test) low gonadotropins and very high estrogens levels. MRI pelvic scan confirmed pubertal type of uterus, bilateral large ovarian follicles with almost cystic formation on the right ovarium and fibrous dysplasia of proximal rigt femur. Although DNA analysis of peripheral blood did not confirm the presence of activating mutation of the stimulatory G-protein alpha subunit gene, we conclued diagnosis of McCune - Albright syndrome based on clinical features. The patient started aromatase inhibitor treatment - letrozole – 2,5 mg per day at the age of 5,5 years of life. After short period of treatment (10 days), massive but short time lasting vaginal bleeding accompanied by decreased levels of estrogens and collapsing of ovarian follicles occured. At the present time girl does not have signs of vaginal bleeding and breast size is reduced to stage M1, puberty is supressed. Unfortunately, she had pathological bone fracture, X ray confirmed multiple cystic lesions mostly on right arm and forarm. She started bisfosfonate treatment with pamidronate acid.

Conclusion: McCune - Albright syndrome is a rare sporadic disorder. Although DNA analysis do not reveal GNAS mutations, the final diagnosis might by made due to clinical features, the most frequent endocrine disorders is precocious puberty due to large ovarian cysts with estrogen hyperproduction. In her case long term letrozol and bisfosfonate treatment as well endocrinological follow up of other hyperfunctional endocrinopathies is needed.