Adrenals

Question 1

Describe the arterial supply to the adrenals.

Answer 1

• superior artery from the phrenic
• middle artery from the aorta
• inferior artery from the renal

Question 2

Describe the venous drainage from the adrenals.

Answer 2

• the left drains into the left renal vein

- the right drains into the IVC

Question 3

What are the three zones of the adrenal cortex and what do they produce.

Answer 3

• granulosa: “salt”/aldosterone
• fasicularis: “sugar”/glucocorticoids
• reticularis: “sex”/androgens and estrogen

Question 4

What features of an adrenal incidentaloma are concerning?

Answer 4

• size greater than 4cm
• Hounsfeld units greater than 10
• increased size over time
• hormonal activity

Question 5

What labs should you send when testing an adrenal incidentaloma?

Answer 5

• urine metanephrines/VMA/catecholamines
• urine hydroxycorticosteroids
• serum K
• plasma renin and aldosterone

Question 6

What results from deficiencies of the following:

• 21 hydroxylase
• 11 hydroxylase
• 17 hydroxylase

Answer 6

• think about aldosterone first and testosterone second with the digit “1” meaning it goes up
• 21: normal aldosterone, increased testosterone
• 11: increased aldosterone, increased testosterone
• 17: increased aldosterone, normal testosterone

Question 7

Hyperaldosteronism

Answer 7

• also known as Conn’s syndrome
• most often due to bilateral idiopathic adrenal hyperplasia
• it presents with hypertension secondary to sodium preservation and hypokalemia due to potassium wasting
• diagnosed based on a plasma aldosterone : renin ratio of greater than 25; confirm with salt load suppression test after which aldosterone remains elevated
• must localize site of secretion with CT, MRI, NP-59 scintigraphy, or adrenal venous sampling
• treat with spironolactone, CCB, and K replacement
• second line is adrenalectomy
• if bilateral, post-op patients require fludrocortisone

Question 8

What is the most common cause of hyperaldosteronism?

Answer 8

bilateral adrenal hyperplasia

Question 9

How is hyperaldosteronism diagnosed?

Answer 9

• hypokalemia
• aldosterone : renin ratio > 25
• hyperaldosteronism despite salt load suppression test
• finally, localized via CT/MRI/NP-59 scintigraphy/adrenal venous sampling

Question 10

How does acute adrenal insufficiency testing present?

Answer 10

with refractory hypotension, fevers, lethargy, pain, nausea, and vomiting

Question 11

How is adrenal insufficiency treated?

Answer 11

dexamethasone and fluids

Question 12

What is the most likely etiology for primary or secondary hypercortisolism?

Answer 12

• adrenal adenoma for primary (low ACTH)

- pituitary tumor or small cell lung cancer (high ACTH)

Question 13

What is Cushing’s disease?

Answer 13

hypercortisolism secondary to a pituitary adrenaloma

Question 14

What drug is used to treat recurrent adrenocortical carcinoma?

Answer 14

mitotane

Question 15

What is the rule of 10s for pheochromocytoma?

Answer 15

• 10% malignant
• bilateral
• in children
• familial
• extra-adrenal

Question 16

Which pheochromocytomas produce epinephrine? Why?

Answer 16

only adrenal because they express the PNMT enzyme

Question 17

What is the pre-operative treatment for pheochromocytomas?

Answer 17

• alpha blockade with phenoxybenzamine

- followed by beta blockade

Question 18

What is the most common extra-adrenal site for pheochromocytomas?

Answer 18

• 10% are extra-adrenal

- most commonly at the organ of Zuckerkandl

Question 19

What is the most common cause of Cushing syndrome?

Answer 19

exogenous steroids

Question 20

What is the most common cause of Addison disease?

Answer 20

• in the first world it is autoimmmune

- in the third world it is TB

Question 21

What test is used to diagnose pheochromocytoma in patients that are normotensive?

Answer 21

clonidine suppression test