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 TgAb and TPOAb, and negative for 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.