Figure 1a. Silent thyroiditis in a 28-year-old woman with hyperthyroidism. Laboratory values were as follows: T4 = 21 µg/dL, T3 = 289 µg/dL, and TSH < 0.02 µIU/mL. RAIU was less than 1% at 24 hours. (a) On a distant anterior scintigram, the thyroid is barely visible (broad arrow at left). The round photopenic area (thick arrow) represents a 2-cm lead marker placed at the suprasternal notch. The dark structures (thin arrow) represent the salivary glands. Because of associated thyromegaly and the patient’s morbid fear of thyroid cancer (as diagnosed in a sibling), large-core needle biopsy was performed. (b) Photomicrograph (original magnification, x150; hematoxylin-eosin [H-E] stain) demonstrates mild lymphocytic infiltration within the thyroid parenchyma.