A 35-year-old man has progressive proximal muscle weakness, new hypertension, easy bruising, truncal weight gain, abdominal striae, a round face and a supraclavicular fat pad. BP 162/98. Labs: high sodium, low potassium, high morning cortisol, low ACTH, no suppression on the 1 mg dexamethasone test, low aldosterone and low renin. What is the most likely diagnosis?
سؤال مجاني 6 من 10 اليوم · اشترك وكمّل بدون حد
اعرض الإجابة
الإجابة والشرح
ادخل لحسابك عشان نحفظ إجاباتك ونوريك أخطاءك.
الإجابة: C. Primary adrenal tumour
Cushingoid features with high cortisol and no dexamethasone suppression confirm Cushing syndrome. Low ACTH makes it ACTH-independent, pointing to a primary adrenal tumour. Cushing disease and ectopic ACTH both have high ACTH. Low renin and aldosterone with hypokalemia reflect cortisol's mineralocorticoid effect suppressing the RAAS. (RT notes link low renin/aldosterone to ectopic ACTH, but the low ACTH here excludes that.)
ليش كل خيار صح أو غلط
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A
ليش غلط
Cushing disease has high ACTH with suppression on high-dose dexamethasone; this patient's ACTH is low.
✓ Step Up To Medicine 6th Edition 2024 (Adrenal).pdf · p. 4 -
B
ليش غلط
An ectopic ACTH tumour also gives high cortisol with high ACTH; this patient's ACTH is low.
✓ Step Up To Medicine 6th Edition 2024 (Adrenal).pdf · p. 4 -
C
ليش صح
High cortisol with low ACTH means the cause is likely an adrenal tumour or hyperplasia, not a pituitary or ectopic ACTH source.
✓ Step Up To Medicine 6th Edition 2024 (Adrenal).pdf · p. 4 -
D
ليش غلط
CAH is defined by decreased cortisol and aldosterone production; this patient has high cortisol and low ACTH.
✓ Step Up To Medicine 6th Edition 2024 (Adrenal).pdf · p. 13
- المصدر
- Adrenal disorders (2).pdf · p. 9
Step Up To Medicine 6th Edition 2024 (Adrenal).pdf · p. 4 - المحاضرة
- Cushing's Syndrome · Endocrinology · Module B
- ظهر في
- MED42 Compre B