Scarred atrophic thyroid after I-131 therapy for Graves' disease documented at autopsy

Radioiodine is used as the definitive treatment of choice in most patients with Graves' hyperthyroidism. Most patients with Graves' disease eventually develop hypothyroidism following I-131 therapy and require thyroid hormone replacement therapy. We present a patient with aortic stenotic cardiac disease and coronary artery disease who suffered from fatigue, weight loss and atrial fibrillation. The patient's radionuclide study, as well as the T4 and TSH, confirmed Graves' disease and he received I-131 therapy. Our patient's development of hypothyroidism following 5 mCi I-131 therapy after seven days later was considered as unusual; in addition, our patient, at autopsy, had documented histopathologic changes confirming atrophy and fibrosis of the thyroid gland.