A 55-year-old female who was recently diagnosed with type 2 diabetes presented with central weight gain over the last 8 months, associated with fatigue and weakness. She also noticed multiple body bruises. On examination her blood pressure is 157/94. Her labs showed: high free urinary cortisol, high morning 8 am cortisol level after administration of 1mg dexamethasone, and low ACTH. What is the most appropriate next step in evaluation ?
سؤال مجاني 9 من 10 اليوم · اشترك وكمّل بدون حد
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الإجابة: C. Adrenal CT
High urinary free cortisol plus non-suppression on 1 mg dexamethasone already establish Cushing syndrome, so another screening test (late-night salivary cortisol) adds nothing. Low ACTH means an ACTH-independent, adrenal source, so the next step is adrenal CT. Brain MRI is for high-ACTH (pituitary) disease, and chest CT is for ectopic ACTH.
ليش كل خيار صح أو غلط
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A
ليش غلط
Two of three screening tests (urine cortisol and dexamethasone suppression) are already positive, which supports Cushing syndrome, so the next step is the cause workup, not another screen.
✓ 6• Cushing's Syndrome & Disease [Notes].pdf · p. 5 -
B
ليش غلط
MRI of the pituitary is for ACTH-dependent Cushing disease (positive high-dose dexamethasone suppression); her ACTH is low.
✓ Endocrine ✳️.pdf · p. 24 -
C
ليش صح
Low ACTH points to an adrenal origin, and the next step is adrenal imaging with CT.
✓ Endocrine ✳️.pdf · p. 24 -
D
ليش غلط
Chest CT/MRI is for ectopic ACTH (no suppression on the high-dose dexamethasone test, likely small cell lung cancer), which needs a high ACTH.
✓ Endocrine ✳️.pdf · p. 24
- المصدر
- Endocrine ✳️.pdf · p. 24
6• Cushing's Syndrome & Disease [Notes].pdf · p. 5 - المحاضرة
- Cushing's Syndrome · Endocrinology · Module B
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- Endo bank