Large Group 2 Flashcards
What is the difference between Cushing’s Disease and Cushing’s Syndrome?
Disease=ACTH secreting pituitary adenoma
syndrome=all causes of excess cortisol (exogenous ACTH tumor, adrenal tumor, excessive GC treatment, ectopic)
What is often the cause of ectopic ACTH release?
small cell lung cancer
What skin issues are seen in Cushing’s disease?
broad cutaneous vilatious striae
easy bruising
red face
What are the 2 classifications of endogenous Cushing’s Syndrome?
ACTH independent (adrenally producing excess cortisol regardless of ACTH level)
ACTH dependent (includes pituitary and ectopic issues producing elevated ACTH causing the excess cortisol)
What do the AM and PM cortisol test and the midnight salivary cortisol test test for?
loss of diurnal variation in cortisol release seen in Cushing’s
AM and PM: AM should be > PM in normal person
midnight salivary: cortisol is expected to be lower at night in normal people.
How does the low dose Dexamethasone test work? What do the results tell you about the cause of the problem?
1mg Dexamethasone given at midnight (it is a long acting deus with no MC activity)
normal=plasma cortisol < 5 mg/dL the next morning
elevated cortisol=pituitary or adrenal problem (look at the starting ACTH levels to determine which)
What is the 24 hour free cortisol test?
have people collect their urine for 24 hours
> 140 nmol/d is suggestive of Cushing’s
Which will produce more ACTH, a pituitary tumor or an ectopic tumor?
ectopic
If an adrenal adenoma is causing Cushing’s, what will the ACTH be? What about a pituitary or ectopic tumor?
adrenal: low ACTH
pituitary or ectopic: high ACTH
How will the different tumors respond to HIGH dose (8mg) Dexamethasone? What does this help determine?
adrenal: cortisol will still be high
ectopic (lung cancer): cortisol will remain high.
Pituitary microadenoma: decrease in the cortisol production (from the feedback inhibition of ACTH)
Pituitary Macroadenoma: cortisol will be HIGH (not responsive to the high Dex)
helps determine micro vs macro adenoma
What is a useful test in determining the difference between a macro adenoma and an ectopic tumor?
since both will maintain high levels of cortisol with high ACTH, a pituitary MRI would help
if no mass is seen, it is likely ectopic
If a pituitary macroadenoma is found, what else should be ordered?
check the different axes for issues
TSH and T4, GH and IGF-1, LH and testosterone
If a pt is having a right adrenalectomy for a right adrenal adenoma, what pre-op and post-op treatment should they receive? Why?
pre-op and post-op glucocorticoids (short-acting) with larger doses in the morning and less at night to mimic the diurnal variation
pre-op to keep blood pressure up and post-op to allow the left adrenal time to begin operating again (may have become less functioning because of the previously elevated cortisol levels due to the adenoma)
What is an adrenal incidentaloma?
a mass lesion > 1 cm that is found serendipitously by a radiologic exam
What do you suspect with HTN, palpitations, sweating and headaches?
pheochromocytoma
Which syndrome is not associated with pheochromocytoma? A. MEN 1 B. MEN 2A C. MEN 2B D. VHL
A. MEN 1 (the 3 P’s that are organs –> pituitary, parathyroid and pancreas)
What are the 3 things affected by MEN 2A?
parathyroid
pheochromocytoma
medullary thyroid cancer
What are the 3 things affected by MEN 2B?
mucosal neuroma
medullary thyroid cancer
pheochromocytoma
When should you consider testing for primary aldosteronism?
HTN and hypkalemia
resistant HTN
adrenal incidentaloma and HTN
HTN onset 160 systolic or >100 diastolic)
whenever considering secondary HTN
What is the screening test for primary aldosteronism? What results are necessary for a diagnosis?
Plasma Aldosterone and Renin
PAC (plasma aldosterone concentration) >15 ng/dL or decreased PRA (20 ng/dL
PRA=renin
How do you confirm a diagnosis of primary aldosteronism?
try to suppress the aldosterone production
have the pt increase their Na+ to 6g/day x3 days and then collect the urine on the 3rd through the 4th day and verify the amount of sodium in the urine
if the aldosterone secretion is high (>12 mcg/24hr), suspect primary aldosteronism (the elevated Na+ and increase in volume should have caused the aldosterone to decrease)
What are the medical treatments available for primary aldosteronism?
mineralocorticoid receptor antagonists
spironolactone–> causes gynecomastia
When would you perform surgery in a pt with primary aldosteronism? what option could be considered if the pt was over the age of 40?
surgery in a pt with a mass >1 cm and marked primary aldosteronism under the age of 40
in a pt with the same symptoms over the age of 40, do AVS (adrenal venous sampling) to ensure that there is lateralization prior to the adrenalectomy
What will the cortisol level and ACTH be in a pt with primary vs secondary adrenal insufficiency?
primary:
cortisol= low
ACTH=high
secondary
cortisol= low
ACTH =low
Will pts with secondary adrenal insufficiency be hyper pigmented?
NO because ACTH will not be elevated
What is a possible cause of primary adrenal insufficiency? Secondary?
primary: adrenal hemorrhage
secondary: sudden cessation of exogenous glucocorticoids
What can a pt who took GC for a long time and suddenly stopped appear as though they have?
Cushings
What test should be done if you suspect adrenal insufficiency?
cosyntropin (synthetic ACTH) stimulation test
if the adrenal gland can be stimulated to make >18 micrograms/dL of cortisol, it rules out adrenal insufficiency
if it cannot make 18 with cosyntropin, and the ACTH at baseline was HIGH, it suggests primary AI
if it cannot make 18 of cortisol and the baseline ACTH was LOW, it suggests secondary AI
How does the treatment differ for primary and secondary adrenal insufficiency?
primary: give both glucocorticoids and mineralocorticoids
secondary: only give glucocorticoids (MC are not under the control of ACTH)
What should a pt with AI be aware of?
they need to supplement steroids in times of stress
