Weight loss, palpitations...

An otherwise healthy middle-aged man reported a 5-kg weight loss, palpitations, and profuse perspiration that had been present for two weeks. He was found to have a generalised goitre, upper-limb tremors, and tachycardia. His initial laboratory tests showed high levels of free thyroxine (4.58 ng/dL) and suppressed thyroid-stimulating hormone (0.005 IU/mL). The thyroid gland was diffusely enlarged in both lobes by technetium-99 thyroid scanning, with a focal increase in radiotracer uptake in the middle of the right lobe. The midzone of the left lobe was likewise found to have a focused photopenic region. The absorption of radiotracers was diffusely increased throughout the rest of the thyroid gland (figure 1). Cytology showed monolayered clusters, micro follicles, and single benign thyroid cells showing enlarged nuclei.