A 53-year-old woman is referred to our clinic with a chief complaint of a neck mass and a hoarse voice. She sought care after feeling a lump in the lower anterior neck, just to the right of the midline. She complains of a sensation of neck tightness, especially when lying supine. She denies any difficulty swallowing, or pain. She denies exposure to ionizing radiation. She takes no medications and has no known drug allergies. Her social history is negative for tobacco and alcohol use. She does not have a family history of neck tumors or thyroid problems. On physical exam, she is a well-nourished normal adult female with a solitary, 2-cm nodule in the right lobe of the thyroid that moves with swallowing. There is no associated cervical adenopathy. Laboratory tests demonstrate a thyroid-stimulating hormone of 2 mIU/L (normal 0.4–4 mIU/L) and normal serum-free thyroxine (T4) and free triiodothyronine (T3) levels. An ultrasound confirms the presence of a roughly spherical, well-demarcated 2-cm nodule in the right lobe of the thyroid and normal cervical lymph nodes.