Unusual Management of a Rare Case of Methimazole-Resistant Graves Disease

As the leading cause of hyperthyroidism, Graves disease (GD) does not often present with its classical triad of pretibial myxedema, goiter, and exophthalmos but instead is often recognized by various manifestations such as tachycardia, weight loss, jaundice, or dermatopathy and requires utmost clinical vigilance. Three treatment modalities for GD exist as antithyroid drugs (ATDs), radioactive iodine (RAI), and surgery, but each bears its own serious side effects. Furthermore, there have been several reports in the literature about ATD resistance that can complicate management. We describe a rare complex case of methimazole (MMI)-resistant GD in a 58-year-old woman with multiple comorbidities including heart failure, atrial fibrillation, liver cirrhosis, and hypertension. She presented with an initial complaint of diffuse swelling and was found to have severe thyrotoxicosis. Despite high doses of MMI, her thyroid function remained significantly elevated. Thyroid uptake and scan while on MMI showed high radioactive iodine uptake. After receiving RAI therapy, her thyroid function and bilirubin improved markedly, liver enzymes remained stable, and anasarca responded to diuretics. This case highlights the challenges in managing resistant GD and emphasizes the necessity of personalized treatment plans.