Thyroid Abnormalities in Children and Adolescents with McCune-Albright Syndrome

Abstract

Background: To date, there is no agreement about the frequency or the features of thyroid abnormalities in McCune-Albright syndrome (MAS). The aim of our study was to detect thyroid abnormalities in a cohort of MAS children and adolescents and to give indications for their treatment and follow-up. Methods: In 36 patients, 22 females and 14 males, thyroid function and sonographic features of thyroid were evaluated every 6–12 months. Results: Three males and 1 female had hyperthyroidism: 2 with nodular, 2 with diffuse goiters. They were treated with methimazole (0.2–0.5 mg/kg/day) with good clinical and biochemical responses. The remaining 32 patients were euthyroid, even if 7 displayed sonographic alterations, of whom 5 had nodular goiter with nodules >1 cm, and 2 micronodular goiter. Fine-needle aspiration biopsy was performed in 2 patients with nodules >1 cm, 1 showing hemorrhagic nodule and 1 colloid cystic nodule. Conclusions: Prevalence of thyroid alterations in the studied MAS series was 31%. 64% of 11 patients with thyroid alterations had nodular goiters, with nodules >1 cm. As the onset of thyroid disease ranged from 1 to 20 years, a strict monitoring of thyroid function is recommended every 6 months. Satisfactory treatment can be obtained and maintained with antithyroid drugs.

Prognostic Factors From an Epidemiologic Evaluation of Fibrous Dysplasia of Bone in a Modern Cohort: The FRANCEDYS Study

“…Only three patients had hyperthyroidism compared with 20-50% of MAS in literature (24). Four patients presented acromegaly compared with 20-30% of MAS in published series (25).…”

Management of hyperthyroidism in children

“…Hyperthyroidism is, after precocious puberty, the second commonest endocrinopathy in MAS, being detectable in around 11% of cases [70]. It depends by the activation of GSα protein in thyroid tissue, which leads to cAMP overproduction, with secondary stimulation of thyrocyte growth and TH hypersecretion.…”

“…MMI treatment, even at lower doses than in GD, usually gives a good clinical and biochemical control of hyperthyroid picture [71], but recurrences after therapy withdrawal are not infrequent, owing to the constitutional TH overproduction [74]. Considering that iatrogenic liver damage is especially dangerous in MAS children, who may have congenital hepatic alterations, PTU should be avoided [70].…”

“…Although MMI therapy is often adopted as first-line option in the management of MAS-related thyrotoxicosis [70,71], nevertheless it has to be considered that surgery may represent a more suitable therapeutic choice, at least in the children with clinically significant nodules, compression symptoms or poorly controlled hyperthyroidism [75,76]. In these selected cases total thyroidectomy has probably to be preferred to other options [70].…”

“…Also RAI therapy has been proposed as an appropriate treatment of MAS thyrotoxicosis [72], but this choice is not very popular, considering that the risk of thyroid carcinoma is already increased in this condition [70,75,76].…”