Adrenal Disorders USMLE Step 1 Practice Question
A 52-year-old woman presents with progressive weakness, fatigue, and darkening skin pigmentation despite minimal sun exposure. Vital signs reveal hypotension (88/52 mmHg), heart rate 102 bpm, and temperature 37.2°C. Laboratory studies show hyponatremia (Na+ 125 mEq/L), elevated ACTH (180 pg/mL; normal <50), and low morning cortisol (2 µg/dL). Thyroid function tests are normal. Which of the following is the most likely diagnosis?
Answer choices
- AAcute adrenal hemorrhage from sepsis
- BCushing syndrome with secondary hyponatremia
- CTertiary adrenal insufficiency from hypothalamic dysfunction
- DPrimary adrenal insufficiency (Addison disease)Correct answer
- ESecondary adrenal insufficiency from pituitary adenoma
- FCentral hypothyroidism with secondary adrenal insufficiency
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