105dren with Graves’ disease who fail to achieve remission after 2 years of antithy-
roid drug therapy should be offered defi nitive treatment, either radioiodine
ablation or surgery. Radioiodine ablation is an effective therapy for children
with Graves’ disease with a cure rate of 95 %. However, it is to be avoided in
children <5 years of age, due to concern for possible risk of thyroid malignancy.
In children with Graves’ disease, high-dose radioiodine therapy should be
employed for complete ablation of thyroid gland, as low-dose radioiodine ther-
apy is associated with an increased risk of neoplasm in irradiated residual thy-
roid tissue. Total/near-total thyroidectomy is indicated in children with large
goiter and in those with age <5 years who fail to achieve remission with anti-
thyroid drugs.- What are the peculiarities of hyperthyroidism associated with McCune – Albright
syndrome?
McCune–Albright syndrome (MAS) is due to post-zygotic activating muta-
tions of Gsα subunit and is characterized by triad of fi brous dysplasia, café-
au- lait macules, and endocrinopathy. Hyperthyroidism is the third most
common endocrine abnormality (19 %) in MAS after precocious puberty
(52 %) and acro-gigantism (27 %). The mean age of presentation of hyperthy-
roidism is 14 years, although it may present as early as in neonatal period.
Children with hyperthyroidism associated with MAS may have diffuse goiter,
multinodular goiter, or solitary nodule. Defi nitive therapy should be offered
to these children as remission does not occur with the use of antithyroid
drugs. - What are the causes of coarse facial features?
Various endocrine disorders are associated with coarse facial features including
acromegaly, hypothyroidism, multiple endocrine neoplasia type 2B syndrome
(MEN2B), pachydermoperiosteitis, and mucopolysaccharidosis. In addition,
patients with morbid obesity, insulinoma, and prolactinomas may also have
coarse facial features. The coarse facial features in acromegaly are due to soft
tissue overgrowth as a result of GH–IGF1 excess. In patients with hypothyroid-
ism, coarse facial features are accompanied with periorbital puffi ness due to
deposition of glycosaminoglycans (GAGs) as a result of high TSH as well as
low T 4. Patients with mucopolysaccharidosis also manifest with coarse features
due to increased extracellular accumulation of GAGs as a result of their
impaired degradation by lysosomal enzymes. Patients with prolactinoma can
also have coarse facial features due to “specifi city-spillover” of prolactin at GH
receptor as a result of structural similarity. Patients with MEN2B have blubbery
lips as a result of mucosal neuromas which may contribute to coarse facial fea-
ture. Altered fi broblast activity and increased sensitivity to gonadal steroids and
epidermal growth factor contribute to coarse facial features in patients with
pachydermoperiostosis (Fig. 3.22 ).3 Thyroid Disorders in Children