[Efficacy of L-thyroxine (L-T4) therapy on the volume of the thyroid gland and nodules in patients with euthyroid nodular goiter (ENG)].

The efficacy of treatment with TSH suppressive doses of L-thyroxine was evaluated by echography in 35 patients with euthyroid nodular goiter. Patients have been subdivided in two groups comparable for sex age and size of the goiter. Sixteen patients were treated for nine months with suppressive doses of thyroxine and nineteen were followed without therapy as control. Patients in treatment were then followed up for additional 9 months without therapy. The mean decrease of thyroid volume at nine months was 25% (27 +/- 10 ml vs 20 +/- 8 ml; p < 0.01). After discontinuation of treatment thyroid volume increased and had returned to base line values after nine months of follow up. In the control group mean thyroid volume had increased by 17.7% at nine months (28 +/- 17 vs 33 +/- 19 ml; p < 0.001). Thyroid nodules in response to thyroid hormone treatment showed a variable behaviour: 30.7% (4/13) of the nodules responded to the therapy with a reduction > to 25% at the ninth month; the remaining nodules were insensitive to the therapy. In conclusion suppressive thyroxine treatment is effective in reducing the goiter, nodules instead are only in part sensitive to the treatment. Thyroxine therapy of euthyroid nodular goiter must be followed for long term since upon thyroxine discontinuation there is a prompt reappearance of the goiter.