THYROID ULTRASONOGRAPHY IN PATIENTS WITH A PREVIOUS EPISODE OF AMIODARONE-INDUCED THYROTOXICOSIS

Amiodarone induced thyrotoxicosis (AIT) occurs most frequently in euth yroid patients with nodular goiter or Graves' disease due to release o f iodine from this iodine rich drug. However, some cases of AIT have b een attributed to an inflammatory process of the thyroid gland due to amiodarone itself. We have studied the echographic pattern of the thyr oid in 11 euthyroid patients who had an episode of AIT 32.4+/-3.6 mont hs earlier due to amiodarone induced thyroiditis. There was a signific ant increase in dyshomogeneous echo patterns and hyperechogenecity whi ch suggests fibrotic lesions. These findings were similar to those obs erved in 10 euthyroid patients who 77+/-12 months earlier had an episo de of subacute thyroiditis (SAT). Thyroid volumes of control subjects and patients with a history of AIT and SAT were 10.9+/-1.4, 8.7+/-1.4 and 9.8+/-1.7, in the order. These values were not significantly diffe rent. These echographic findings, normal serum thyroid hormone and TSH concentrations and the absence of circulating antithyroid peroxidase antibodies suggest that underlying thyroid autonomy and Graves' diseas e were not the cause of the previous episode of AIT. The presence of h yperechogenic and dyshomogeneous patterns appears the result of the he aling of the inflammatory AIT process.