ABSTRACT
The effect of thyroxine [L-T4] administration on the size of cold thyroid nodules was evaluated in a retrospective study. In 108 patients, 96 women and 12 men, residing in Tehran-an area of iodine deficiency-85% of the patients were between 20 and 50 years of age. Three months after treatment with L-T4, 9% of the nodules disappeared, 40% decreased in size, 48% were unchanged and 3% increased in size. Five out of six pea-size nodules disappeared after three months of treatment. The effect of L-T4 on the size of thyroid nodules was not affected by the T4 dosage, continuing treatment up to six months, and presence or absence of goiter. This study demonstrates that treatment with L-T4 is an effective method in shrinking the cold thyroid nodules in Tehran