Graves' disease diagnosed nearly six months after microwave ablation of benign thyroid nodules: a case report

Background: Microwave ablation is a new, minimally invasive technique for the treatment of thyroid nodules. Hyperthyroidism due to destructive thyroiditis is a known risk of microwave ablation, though it occurs in only a minority of cases. We report a rare case of a patient diagnosed with Graves' disease nearly six months after undergoing microwave ablation of a thyroid nodule.

Case presentation: On July 31, 2022, a 43-year-old male patient presented to our hospital with symptoms of pyrexia, excessive sweating, and palpitations lasting for 15 days. History inquiry revealed that the patient had undergone microwave ablation of right-sided thyroid nodule nearly five months ago at another hospital. The patient's thyroid ultrasound suggested bilateral diffuse thyroid lesions, with a moderately echogenic mass observed on the right side of the thyroid gland, potentially indicative of thyroid nodule ablation. The patient had elevated serum thyroid hormone levels, decreased thyroid-stimulating hormone levels and positive associated thyroid antibodies. To control the symptoms of hyperthyroidism, the patient opted for oral antithyroid medication, and thyroid hormonal levels returned to normal after 3 months of treatment. The patient is now under regular follow-up.

Conclusions: In this case, we presented the onset of Graves' disease following microwave ablation in a patient with subclinical thyroid autoimmunity. While the causal relationship between microwave ablation and Graves' disease remains unproven, this case suggests that preexisting autoimmune thyroid conditions may increase susceptibility to postoperative thyroid dysfunction. Procedural factors, such as thermal injury to surrounding tissues and potential involvement of the autonomic nervous system, are also potential contributors to the development of Graves' disease following microwave ablation.