Chempath 15: Adrenal Disease

Question 1

What are the 3 zones of the adrenal cortex ?

Answer 1

Zona glomerulosa
Zona Fasciculata
Zona Reticularis

Question 2

In which zone of the adrenal cortex is aldosterone produced ?

Answer 2

Zona Glomerulosa

Question 3

In which zone of the adrenal cortex is cortisol produced ?

Answer 3

Zona fasciculata

Question 4

In which zone of the adrenal cortex are androgens such as DHEA produced ?

Answer 4

Zona reticularis

DHEA (dehydroepiandosterone) is a precursor to male and female sex hormones including oestrogen and testosterone

Question 5

Where is adrenaline produced ?

Answer 5

Adrenal Medulla

Question 6

List 2 potential causes of hyperplastic Adrenal glands ?

Answer 6

Cushing’s disease 
Ectopic ACTH (e.g lung tumour)

Question 7

Where does the Right adrenal gland drain into ?

Answer 7

Inferior vena cava (IVC)

Question 8

Where does the left adrenal gland drain into ?

Answer 8

Left renal vein

Question 9

What is schmidt’s syndrome ?

Answer 9

A syndrome of co-existing hypothyroidism and Addison’s disease due to autoantibodies against both the thyroid and the adrenals

Hyponatraemia + hyperkalaemia (mineralocorticoid deficiency)
Hypoglycaemia (glucocorticoid (cortisol) deficiency)
low T4 high TSH (Primary hypoparathyroidism)

Aka polyglandular autoimmune syndrome type II

Question 10

Which test is used to diagnose Addison’s disease ?

Answer 10

Short synACTHen test

Question 11

Explain how the short synACTHen test works and what results you would expect in Addison’s disease ?

Answer 11

1)- measure initial cortisol +ACTH
2)- Administer synthetic ACTH 250mcg by IM injection
3)- check cortisol at 30 and 60 mins
In normal people cortisol should be able get to >550 nM within 30 mins

In Addison’s disease Cortisol does increase after synthetic ACTH and stays <10nM

Question 12

Which test is used to diagnose phaeochromocytoma ?

Answer 12

Urine catecholamines - high = phaeochromocytoma

Question 13

What is a phaeochromocytoma ?

Answer 13

An adrenal medullary tumour that secretes adrenaline causing hypertension, arrhythmias, sweating, impending sense of doom

Question 14

List 3 genetic conditions in which phaeochromocytoma is seen ?

Answer 14

MEN2
Von Hippel Lindau syndrome
Neurofibromatosis type 1

Question 15

List 3 features of MEN2a?

Answer 15

Parathyroid tumours
Medullary thyroid cancer
Phaeochromocytoma

Question 16

List 4 features of Von Hippel Lindau syndrome ?

Answer 16

Phaeochromocytoma
Renal cell carcinoma
Renal cysts
Retinal/CNS haemangioblastomas

Question 17

List up to 6 features of Neurofibromatosis type 1

Answer 17

Peripheral and spinal neurofibromas 
Cafe au lait spots
Axillary freckling 
Lisch nodules on iris 
Phaeochromocytoma 
Renal artery stenosis

Question 18

What is Conn’s syndrome ?

Answer 18

Primary hyperaldosteronism causing hypertension, hypokalaemia and inhibition of renin secretion

Question 19

Which test can be done to diagnose Conn’s syndrome ?

Answer 19

Serum aldosterone: renin levels

Conn’s: high Aldosterone:renin ratio

Question 20

How can you test for Cushing’s ?

Answer 20

9am cortisol
12pm midnight cortisol (if low then very strong negative predictive value that it is not Cushing’s)
Low dose dexamethasone suppression test
0.5 mg dexamathasone every 6hrs for 48 hours ( if cortisol not suppressed then Cushing’s)

Question 21

Which tests can help differentiate Cushing’s syndrome from Cushing’s disease?

Answer 21

High dose Dexamethasone suppression test- pituitary tumour secreting ACTH shows some suppression in cortisol. Adrenal ACTH tumours are not suppressed.

Inferior petrosal sinus sampling (IPSS)- sampling of the pituitary for an ACTH secreting tumour
85% cause of endogenous Cushing’s syndrome is Cushing’s disease

Question 22

Why is IPSS preferred to High dose dexamethasone suppression test?

Answer 22

High dose dexamethasone test has a 20% false positive rate

Question 23

List 3 features of MEN2b ?

Answer 23

Phaeochromocytoma
Medullary thyroid cancer
G.I tract mucocutaenous neuromas

Question 24

Differential diagnosis of an adrenal mass

Answer 24

Phaeochromocytoma
Conns syndrome
Cushing’s syndrome

Question 25

Treatment for a phaeo

Answer 25

Medical emergency
1- alpha blockade (phenoxybenzamine)
Leads to sudden BP drop so give fluids

2- beta blockade
To treat reflex tachycardia

Surgery

Question 26

What is pseudo Cushing’s syndrome

Answer 26

Obesity can change your metabolism of cortisol and produce a picture that looks like Cushings

Question 27

List the endogenous and exogenous causes of Cushing’s syndrome

Answer 27

Endogenous 
Pituitary dependent Cushing’s disease (85%) 
Adrenal adenoma (10%) 
Ectopic ACTH ( 5%) 

Exogenous
Oral steroids