ESPE Abstracts

Background: McCune-Albright Syndrome(MAS）is a rare disease caused by somatic gain-of-function mutations of the GNAS gene, presenting with fibrous dysplasia(FD), cafe-au-lait spots and gonadotropin-independent precocious puberty(PP). Adenohypophyseal hyperfunction syndromes is reported uncommon but potentially severe complication of MAS.

Method: A prospective study was performed to evaluate the prevalence of the pituitary hyperfunction syndromes in children and adolescents with MAS.

Result: 1. From 2002 to 2019, 175 girls who presented PP were diagnosed MAS. First visiting age was 4.00 (0.75-8.17）years. 15 girls (8.6%) had pituitary hyperfunction, in whom, 7 cases (46.6%) were typical types, 7 cases (46.6%) had cafe-au-lait spots accompanied with pp, and 1(6.8%) had PP only. 2. In the 15 cases, only 3 were confirmed pituitary adenomas by MRI scans,2 were macro-adenomas, another one was micro-adenomas. 5 cases had GH excessive accompanied with hyperlactinemia, while 8 had hyperlactinemia only, and 2 had isolated excessive GH secretion. In cases with excessive GH secretions, fasting GH levels were 1.02-22.28 ng/ml, and the standard deviation scores (SDS) of serum levels of IGF-1 were 2.17(-0.9-3.85SD). GH levels after oral glucose tolerance tests were 0.97-20.56ng/ml. Serum PRL levels in girls with hyperlactinemia ranged from 42.85-1036ng/ml. 7 patients also had other endocrinopathies: 4 hypercortisolism, 3 thyroid abnormalities. 3. In patients with hyperlactinemia, only 3 girls with typical traid occurred lactation. 1 had hyperlactinemia since 4.5 years old, but presented lactation, accompany with over growth and facial, extremities asymmetric at 14.33 years of age. Another one had normal pituitary functions at first visiting, but had hyperlactinemia and lactation 5 years later. 4. All accepted letrozole or tamoxifen treatment for the PP. In patients with lactation, Bromocriptine was combined. GH and PRL levels decreased in 2cases after treatment but still fluctuated. One had transsphenoidal pituitary tumor resection finally.

Conclusion: 1. Adenohypophyseal hyperfunctions is rare in children wiith MAS, and it is more common in patients with typical traid or combined with FD. 2. Although adenomas can be found, normal findings or adenohypophyseal hyperplasia can present in some children who have pituitary hyperfunctions. The status of adenohypophyseal hyperfunction can be variable from mild to severe along with age. Therefore, long-term follow up is recommended in the cases with high risks, even though no clinical manifestations presented or only negative findings by MRI scans. 3. Hyperlactinemiar can be corrected by bomocriptine in children with, however, in some cases other therapy may be needed.