Toxic thyroid adenoma is one of the most important causes of hyperthyroidism. It occurs more frequently in women, older subjects and areas of iodine deficiency but the incidence of the disease is quite variable (2 to 33%). Recent studies suggest that a mutation of the gene expressing TSH receptor or G protein is related to the pathogenesis of the adenoma. Clinical features of toxic thyroid adenoma are similar to those observed in other types of thyrotoxicosis, but usually the symptomatology is mild. Cardiovascular manifestations are frequently reported in these patients, who also have a thyroid nodule, increased levels of thyroid hormones and supressed TSH. Clinical diagnosis is confirmed by a hot nodule at thyroid scintigraphy using 131I, 123I or 99mTc. Clinical control of thyrotoxicosis is obtained by surgery or radioiodine therapy and, more recently, by ultrasound guided percutaneous injection of ethanol in the nodule. Spontaneous regression of the disease in rare.
Toxic thyroid adenoma; Autonomous thyroid nodule
