This 18-year-old girl presented with complaints of swelling in the neck, weight loss, bulging of the eyes, tremor, decreased heat tolerance, loose stools, and occasional palpitations. Physical examination revealed normal blood pressure, resting tachycardia of 110 beats per minute, mild exophthalmos, eyelid lag, and a diffusely enlarged thyroid gland. Pertinent laboratory findings were thyroxine (T4) level 30.8 mcg/dL, free thyroxine was 2.7 ng/dL, and thyroid stimulating hormone (TSH) was 0.22 mcIU/mL. She was given propylthiouracil until she became nearly euthyroid, at which time a thyroidectomy was done. The thyroid gland weighed 45 grams. It was beefy red in color and had a homogeneous fleshy consistency.