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Old 11-25-2009
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Question Nelson Syndrome

I used to remember what's Nelson Syndrome but now I forgot.
Can you please remind me what it it?

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Old 11-25-2009
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Hypercortisolism has four major causes
  • Cushing's Disease (Pituitary adenoma)
  • Ectopic ACTH
  • Adrenal adenoma
  • Iatrogenic (Steroids therapy)

They all present with similar signs and symptoms and can be differentiated using the high dose dexamethasone suppression test.

If by mistake you do bilateral adrenalectomy thinking that's it's adrenal cause of cushing while in fact the patient is having pituitary adenoma, this will result in Nelson syndrome.

They will have even more ACTH production (as you removed the negative feedback from adrenal cortisol) and hence more hyperpigmentation.

Nelson syndrome has become very rare in US and it's unlikely to be tested in USMLE.
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Old 11-28-2009
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Default Nelson syndrome.

1.Bilateral adrenalectomy causes enlargement of preexisting pituitary adenoma . Sudden drop in in cortisol causes an increase in synthesis of ACTH.
2. It is a form of Cushing syndrome.
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Mariahadi (09-25-2014), obgynaim (11-28-2009), rigbbm (09-09-2019), Taiwan_Guy (05-16-2011), Usmle16Forall (09-11-2017), wahaha007 (01-19-2010)


Endocrine-, Pathology-, Syndromes-Acronyms

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