A 25-year-old Caucasian woman presents to her physician’s office concerned that she is beginning menopause due to “hot flashes” that she describes as feeling hot all the time. She also complains of...

A 25-year-old Caucasian woman presents to her physician’s office concerned that she is beginning menopause due to “hot flashes” that she describes as feeling hot all the time. She also complains of weight loss, diarrhea, and insomnia. Her physical exam is positive for a staring gaze with lid lag, tachycardia, and scaly thickened seminodular areas of induration over her tibia. Her labs revealed elevated T3 and T4, decreased TSH, and diffusely increased uptake of RAI (in her thyroid). What is her diagnosis?

A. Toxic adenoma

B. Subacute granulomatous thyroiditis

C. Graves disease

D. Hashimoto thyroiditis