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Old 01-18-2012
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Default endocrine pathology Q2

8 A 40-year-old man sees his physician because he has had headache, weakness, and a 5-kg weight gain over the past 3
months. He has experienced mental depression for the past 3 months and has been prescribed antidepressants. On
physical examination, his face is puffy. His temperature is 36.9°C, pulse is 79/min, respirations are 15/min, and blood
pressure is 160/75 mm Hg while lying down. He has cutaneous striae over the lower abdomen and ecchymoses scattered
over the extremities. A radiograph of the spine shows a compressed fracture of T11. Laboratory findings show a fasting
plasma glucose level of 200 mg/dL, serum Na+ of 150 mmol/L, and serum K+ of 3.1 mmol/L. The plasma cortisol level is
38 μg/dL at 8:00 am and 37 μg/dL at 6:00 pm. Administration of low and high doses of dexamethasone fails to suppress
the plasma cortisol level and excretion of urinary 17-hydroxycorticosteroids. The plasma corticotropin level is 0.8 pg/mL.
Which of the following lesions is most likely to be present in this man?
□ (A) Adenoma of the right adrenal cortex with atrophy of the contralateral adrenal cortex
□ (B) Small-cell carcinoma of the lung with bilateral hyperplasia of the adrenal cortex
□ (C) Corticotroph adenoma of the anterior pituitary with bilateral hyperplasia of the adrenal cortex
□ (D) Adenoma of the right adrenal cortex without atrophy of contralateral adrenal cortex
□ (E) Corticotroph adenoma of the anterior pituitary, medullary carcinoma of thyroid, and bilateral nodular hyperplasia
of the adrenal cortex
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Old 01-18-2012
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i think A)
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Old 01-18-2012
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B.

the fact that both low and high does dexamethasone failed to suppress cortisol levels is indicative of ectopic ACTH stimulation (ie. lung cancer).

the rest is gibberish imo.
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Old 01-18-2012
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should be B ........ but can be A because an Adenoma secreting cortisol will lower Acth and cause other normal gland to atrophy and even adrenal tumours are not suppressed by high dexamethasone , the only way to differentiate the small cell ca and adenoma is acth which is low in adenoma but is not given in the question so dont know ....

if any one finds a better way pl tell me know .....
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Old 01-18-2012
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I] also think its A. since corticotropin level is decreased.If it was B then corticotropin level should be high
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Old 01-19-2012
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Quote:
Originally Posted by mohitkmc View Post
I] also think its A. since corticotropin level is decreased.If it was B then corticotropin level should be high

correct , my bad , didnt see it ........
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Old 01-19-2012
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Correct Answer the correct answer is > A

the correct answer is A , as here due to the cotisol level is not suppressed by low and high dexamethasone so it is not cushing disease ( the disease in pituitary) so it is cushing syndrome wheter the cause is ectopic or adrenal adenoma and to differenite we see the ACTH level in ectopic it should be very high while in adenoma is low due to feed back effect which causes also the atrophy of the contralateral adrenal gland
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