Cushing's Syndrome

Question 1

What is Cushing’s syndrome?

Answer 1

Excess cortisol

Question 2

What are the symptoms of Cushing’s syndrome?

Answer 2

Moon face
Central obesity 
Purple striae
'Buffalo hump'
Hypertension 
Diabetes 
Depression

Question 3

What is Cushing’s disease?

Answer 3

Pituitary adenoma producing ACTH

Question 4

What else can produce excess ACTH?

Answer 4

SCLC

Question 5

What are the investigations for suspected Cushing’s syndrome?

Answer 5

Bloods

• FBC
• U+Es
• CRP
• 9am cortisol
• ACTH

24h urine cortisol

Dexamethasone suppression test

Question 6

What time should cortisol levels in the blood be measured?

Answer 6

9am

Question 7

What is the dexamethasone suppression test?

Answer 7

Give dose of dexamethasone and measure cortisol

Cortisol should decrease due to negative feedback

Question 8

What happens in low dose dexamethasone suppression test?

Answer 8

Increased cortisol = Cushing’s syndrome

Question 9

What happens in high dose dexamethasone suppression test?

Answer 9

Decreased cortisol = pituitary problem
- as some feedback control

Increased cortisol = ectopic source

Question 10

How is Cushing’s syndrome managed?

Answer 10

Treat cause

Tumour = removal of tumour

Exogenous steroids = stop steroids

Question 11

What drugs can be given for Cushing’s syndrome?

Answer 11

Metyrapone

Ketoconazole

Question 12

What is the action of the drugs?

Answer 12

Inhibit cholesterol synthesis

So inhibit production of cortisol