A 28-year-old woman presents with progressive weight loss despite increased appetite, heat intolerance, anxiety, and palpitations for 6 weeks. Vital signs show BP 148/82 mmHg, HR 112/min, RR 18/min, temperature 37.8°C. Physical examination reveals diffuse nontender goiter, fine tremor, and bilateral exophthalmos. TSH is suppressed at 0.02 mIU/L with elevated free T4 at 18 ng/dL. Thyroid peroxidase antibodies are negative. Which of the following best describes the pathophysiologic mechanism of her disease?
- A)Autoantibodies against thyroid peroxidase
- B)Iodine deficiency causing increased TSH
- C)Destruction of the thyroid by granulomatous inflammation
- D)Mutation activating RET in parafollicular cells
- E)Autoantibodies stimulating the TSH receptorGABARITO
Explicação
Graves disease is caused by IgG autoantibodies that stimulate the TSH receptor, leading to diffuse thyroid hyperplasia and excess thyroid hormone production. Ophthalmopathy and pretibial myxedema are distinctive extrathyroidal features due to fibroblast activa... Ver explicação completa e trilha adaptativa →