Aim: To study the effect of thyroxine treatment on the size of thyroid nodules in children with Hashimotos thyroiditis
Patients and methods: Twenty-two girls and 6 boys (78.6/21.4%) were followed for 2 years under thyroxine therapy, at mean dose 1.6±0.4 μg/kg per day. Diagnosis of Hashimotos thyroiditis was based on the high value of either antithyroid antibodies, ATPO or ATG. Age at presentation was 10.6±2.0 year (6.213.6). Nineteen patients were pubertal and 9 prepubertal (67.9/32.1%). Thirteen (46.4%) were euthyroid, 12 (42.9%) with subclinical hypothyroidism and 3 (10.7%) hypothyroid. The size of thyroid nodules was 0.97±0.38 cm (0.62.2). All nodules ≥1 cm were examined by FNA that confirmed Hashimotos thyroiditis. For the statistical analysis, t-test and MannWhitney test were used.
Results: At presentation, there was not any significant difference in nodule size between euthyroid children and children with hypothyroidism or subclinical hypothyroidism, 0.9±0.2 vs 1.0±0.4 cm, respectivelly, P>0.05. Nodules size ≥1 cm had 42.9% of children (N=12). Decrease in nodule size ≥0.3 cm after 2 years with thyroxine was observed in 75.0% (N=21). Overall, nodule size showed significant decrease, from 0.97±0.38 cm at start of thyroxine to 0.64±0.48 cm, P<0.001, after 1 year and to 0.65±0.47 cm, P<0.001, after 2 years of treatment. Separately, in euthyroid children nodule size decreased from 0.96±0.30 cm at start of thyroxine, to 0.58±0.48 cm, P=0.027, after 1 year and to 0.63±0.46 cm, P=0.045, after 2 years under treatment. In children with hypothyroidism or subclinical hypothyroidism, nodule size decreased from 1.00±0.43 to 0.69±0.49 cm, P=0.024, after 1 year and to 0.68±0.49 cm, P=0.007, after 2 years under treatment.
Conclusions: Treatment with thyroxine in children with thyroid nodules due to Hashimotos thyroiditis can significantly decrease the size of the nodules, in children with euthyroidism and in those with hypothyroidism or subclinical hypothyroidism, as well.