Development of Graves' Disease after Resection of an Autonomously Functioning Thyroid Nodule

We herein report a 46-year-old woman with autonomously functioning thyroid nodules (AFTNs) who developed Graves' disease (GD) approximately one year after AFTN resection. Before surgery, the patient was positive for anti-thyroglobulin antibodies (TgAb) and anti-thyroid peroxidase antibodies (TPOAb), and negative for TSH-receptor antibodies (TRAb). An AFTN is a follicular adenoma surrounded by chronic thyroiditis. At the onset of GD, her TgAb and TPOAb titers increased, and TRAb became positive. This case suggests that surgery releases a large amount of thyroid tissue that contains thyroid-stimulating hormone receptors, leading to GD in susceptible individuals. Preoperative chronic thyroiditis can predict the postoperative development of GD.