Single thyroid nodules are rare in childhood and adolescence. These nodules may be nonfunctioning, as is the case for the majority of benign adenomas,1 or functioning. Functioning thyroid nodules may be nonautonomous2 or autonomous. Data on the occurrence of autonomous thyroid nodules are scarce. Autonomous nodules function independently of the pituitary-thyroid axis; they do not respond to thyroid-stimulating hormone (TSH) nor are they suppressed by thyroxine therapy.3 Such nodules have been reported in both euthyroid4-7 and hyperthyroid individuals.1.8-12 The term "toxic adenoma" describes only the latter group of patients.
The purpose of this report is to describe two girls who had hyperthyroidism and unilateral thyroid enlargement and in whom no other thyroid tissue could be palpated. The first patient had a toxic adenoma of the thyroid gland, whereas the second patient had Graves' disease with congenital absence of the contralateral lobe. The similar clinical presentation