Appearance of Graves’ disease after percutaneous ethanol injection for the treatment of hyperfunctioning thyroid adenoma

In this report we describe an unusual patient with hyperfunctioning thyroid adenoma in whom percutaneous ethanol injection (PEI) thera py was followed by typical Graves’ disease. His history revealed the presence of a sister with Hashimoto’s thyroiditis. 99-mTc thyroid scintiscan showed focal uptake in the nodule, with suppression of extranodular parenchyma. PEI therapy was followed by the development of severe hyperthyroidism. One month after a second PEI cycle, recurrence of hyperthyroidism associated with diffuse 99-mTc uptake by the gland was observed. TSH-receptor and thyroglobulin autoantibodies were undetectable before PEI therapy, appeared during the first cycle, and showed a further increase after the second PEI therapy cycle. Though spontaneous switch to Graves’ disease cannot be excluded in patients with toxic nodules, the massive release of thyroid materials from follicular cells, among these TSH-receptor antigenic components partially denatured by ethanol, may indeed trigger an autoimmune response to the TSH-receptor, thus accounting for this observation. Patients with possible autoimmune disposition, as selected by familiar history and/or laboratory markers should be carefully monitored during PEI treatment.