Thyroid Disorders USMLE Step 1 Practice Question
A 45-year-old woman presents with progressive fatigue, constipation, and 8-pound weight gain over three months. Vital signs show BP 128/82, HR 58, RR 14, temp 36.8°C, SpO2 98%. Physical examination reveals a diffusely enlarged, painless thyroid. Laboratory studies demonstrate TSH 12.4 mIU/L (normal 0.4–4.0), free T4 0.6 ng/dL (normal 0.8–1.8), and positive anti-thyroid peroxidase antibodies. Thyroid ultrasound shows homogeneous echotexture without nodules. She denies neck pain. Which of the following is the most likely diagnosis?
Answer choices
- AHashimoto thyroiditisCorrect answer
- BToxic multinodular goiter
- CMedullary thyroid carcinoma
- DGraves disease
- ESubacute granulomatous thyroiditis
- FPrimary hypothyroidism due to iodine deficiency
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