An obese woman has a moon face, purple abdominal striae and proximal weakness. Which is the first-line screening test for Cushing syndrome?
Answer and explanation
Correct answer: C. A 24-hour urinary free cortisol, late-night salivary cortisol or dexamethasone suppression test
- Step 1: Screening confirms cortisol excess before the cause is sought. Step 2. Guidelines advise one or more screening tests that show loss of normal cortisol regulation. Answer: A 24-hour urinary free cortisol, late-night salivary cortisol or dexamethasone suppression test. Why not the others: A random sodium is nonspecific. A glucose test with growth hormone is for acromegaly. Prolactin is for pituitary adenoma, not for Cushing's screening.
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