Adrenal Flashcards
What is the arterial supply to the adrenals?
- superior: phrenic
- middle: aorta
- inferior: renal artery
What is the venous drainage of the adrenals?
- left into the renal vein
- right into the IVC
What are the zones of the adrenals?
- Glomerulosa: aldosterone (salt)
- Fasicularis: glucocorticoids (sugar)
- Reticularis: androgens/estrogen (sex)
The adrenal cortex and medulla are derived from which embryologic layers?
- cortex: mesoderm
- medulla: ectoderm
What features of an adrenal incidentaloma are concerning?
- size > 4cm
- HU > 10
- enlarging on serial imaging
- hormonally active
What tests are used to screen for a functional adrenaloma?
- urine metanephrines/VMA/catecholamines
- urine hydroxycorticosteroids
- serum K
- plasma renin and aldosterone levels
What are the congenital adrenal hyperplasias?
think that 1 means elevated (aldosterone/testosterone)
21
17
11
How can you differentiate primary from secondary hyperaldosteronism?
- primary: low renin
- secondary: high renin
What lab test is diagnostic of secondary hyperaldosteronism?
aldosterone/renin > 25
How is hyperaldosteronism diagnosed?
- perform a salt load suppression test, urine aldosterone will remain elevated
- then localize with CT/MRI/NP-59 scintigraphy/venous sampling
What is the most common cause of hyperaldosteronism?
bilateral idiopathic adrenal hyperplasia
How is hyperaldosteronism treated?
- spironolactone, potassium replacement, and calcium channel blockers
- adrenalectomy
How is hypocortisolism diagnosed?
- see decreased cortisol and aldosterone with high ACTH
- perform a cosyntropin stim test and will see persistently low cortisol
How does acute adrenal insufficiency present?
with refractory hypotension, fevers, lethargy, pain, and nausea/vomiting
What is the most common cause of Cushing’s?
exogenous corticosteroids
If a patient has hypercortisolism, what is the differential for low or high ACTH?
- low: adrenal adenoma
- high: pituitary tumor/small cell lung cancer
What is the adjuvant therapy for adrenocortical carcinomas?
mitotane
What is the rule of 10s for pheochromocytoma?
- 10% malignant
- 10% bilateral
- 10% in children
- 10% familial
- 10% extra-adrenal
Which pheochromocytomas produce epinephrine? Why?
adrenal ones because they have the PNMT enzyme
How should adrenalectomy be performed for pheochromocytoma?
ligate the vein first to avoid spillage
What is the most common extra-adrenal location of pheochromocytoma?
the organ of zuckerkandl
What is the most common cause of adrenal insufficiency in 1st and 3rd world countries?
- 1st: autoimmune
- 3rd: TB
