Thyroid Disorders USMLE Step 1 Practice Question
A 68-year-old man with chronic atrial fibrillation on warfarin presents with fatigue, weight loss, and heat intolerance. TSH is suppressed at 0.08 mIU/L and free T4 is elevated at 22 pg/dL. Thyroid ultrasound shows multiple nodules without suspicious features. TSH receptor antibodies (TRAb) are negative. Which of the following is the most likely diagnosis?
Answer choices
- ASubacute thyroiditis
- BToxic multinodular goiterCorrect answer
- CGraves disease
- DThyroid hormone contamination from warfarin interaction
- ESecondary hyperthyroidism from pituitary adenoma
- FHyperthyroidism from functioning metastatic differentiated thyroid carcinoma
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