A1
(A1). There is no doubt that this girl has clinical and laboratory features of Hypothyroidism. Elevated serum TSH and low Free T4 are confirmatory of Clinical Hypothyroidism. Due to the short stature (stunted growth) and delayed puberty this could be a long-standing condition. It may be associated with:
(a). Juvenile chronic autoimmune thyroiditis is a good hypothesis to be considered. However serum thyroid antibodies were repeatedly negative and the thyroid gland was not visible and palpable.
(b). Monogenic disorders of the thyroid system: Common genetic disorders affecting the thyroid will induce a neonatal goiter (goitrous congenital hypothyroidism) that is absent here.
©. Dysgenesis of the Thyroid: it is a good possibility. Ectopic thyroid tissue (lingual thyroid) is a rather frequent finding and may provide some thyroid hormone during the first few years after birth. At puberty the ectopic thyroid tissue is unable to supply the body with adequate thyroid hormone concentrations.
B- What would you do confirm the diagnosis?
B1--Ultrasonography of the cervical area