Adrenals

Question 1

1. What are the five layers of the adrenal gland?

Answer 1

Capsule
Glomerulosa 
Fasciculata 
Reticularis 
Medulla

Question 2

2. What can cause adrenal glands to appear wasted?

Answer 2

Addison’s disease

Long-term steroid use

Question 3

3. What can cause adrenal glands to become hyperplastic?

Answer 3

Cushing’s disease

Ectopic ACTH

Question 4

4. By what factor is the output of cortisol from the adrenals greater than the output of aldosterone?

Answer 4

About 1000 (aldosterone is measured in picomoles, cortisol is measured in nanomoles)

Question 5

5. How many arteries and veins do the adrenal glands have?

Answer 5

57 small arteries

1 vein

Question 6

6. How is a blood sample to measure adrenal output taken?

Answer 6

A cannula is placed through the IVC into the adrenal vein

Question 7

7. How is the venous drainage different for the left and right adrenal glands?

Answer 7

Left – drains into the left renal vein

Right – drains directly into the IVC

Question 8

8. What is the term used to describe the co-existence of primary hypothyroidism and Addison’s disease?

Answer 8

Schmidt syndrome

Question 9

9. Describe the short synacthen test.

Answer 9

Measure cortisol and ACTH at the start of the test
Administer 250 µg synthetic ACTH by IM injection
Check cortisol at 30 and 60 mins
Healthy people should produce > 550 nM of cortisol within 30 mins

Question 10

10. What is the differential diagnosis for hypertension with an adrenal mass?

Answer 10

Phaeochromocytoma
Conn’s syndrome
Cushing’s syndrome

Question 11

12. What are the disastrous consequences of phaeochromocytoma?

Answer 11

Severe hypertension
Arrhythmia
Death

Question 12

13. Outline the treatment of phaeochromocytoma.

Answer 12

Urgent alpha blockade (with phenoxybenzamine or phentolamine or doxazocin)
Some fluids may be given before alpha blockade as it can cause a dramatic drop in blood pressure
A beta-blocker should be given after the alpha-blocker to prevent reflex tachycardia
Patients should receive high-dose alpha and beta-blockade before surgery as the action of surgery can cause the release of catecholamines from the adrenals

Question 13

14. Name three genetic syndromes associated with phaeochromocytomas.

Answer 13

MEN2
Von Hippel Lindau syndrome
Neurofibromatosis type I

Question 14

15. Describe the levels of aldosterone and renin in Conn’s syndrome.

Answer 14

High aldosterone

Low renin

Question 15

16. List some tests used in Cushing’s syndrome.

Answer 15

9 am cortisol
Midnight cortisol
Low-dose dexamethasone suppression test
Inferior petrosal sinus sampling

Question 16

17. Describe how a low-dose dexamethasone suppression test is performed.

Answer 16

The patient’s baseline ACTH and cortisol is measured at the start
Then they are given 0.5 mg dexamethasone every 6 hours for 48 hours
This should suppress cortisol to < 50 nM
If there is failure of suppression of cortisol, the patient should be sent for inferior petrosal sinus sampling

Question 17

18. What is pseudo-Cushing’s syndrome?

Answer 17

Obesity can change your metabolism of cortisol to produce a clinical syndrome that looks like Cushing’s syndrome

Question 18

19. What proportion of endogenous Cushing’s syndrome is caused by Cushing’s disease?

Answer 18

85%

Question 19

20. List three endogenous causes of Cushing’s syndrome.

Answer 19

Pituitary-dependent Cushing’s disease
Adrenal adenoma
Ectopic ACTH