30 - Hypercortisolism

Question 1

What is hypercortisolism also known as?

Answer 1

Cushing’s syndrome

Question 2

Features of hypercortisolism (Cushing’s)?

Answer 2

Weight gain despite healthy lifestyle
Easy bruising
Abdominal striae

Question 3

First cause of Cushing’s syndrome to exclude?

Answer 3

Exogenous corticosteroid use

Question 4

First-line test in suspected Cushing’s syndrome?

Answer 4

Overnight low-dose dexamethasone suppression test (once steroid drug use has been excluded)

Question 5

Once endogenous hypercortisolism is confirmed via overnight low-dose dexamethasone suppression test, what should be measured?

Answer 5

Plasma ACTH

Question 6

If plasma ACTH is suppressed following dexamethasone suppression test, where should diagnostic testing be focused?

Answer 6

On the adrenal glands for intradrenal causes of hypercortisolism
- adrenal CT

Question 7

If plasma ACTH is not suppressed following dexamethasone suppression test, where should diagnostic testing be focused?

Answer 7

On pituitary or ectopic causes of hypercortisolism

- pituitary MRI

Question 8

Investigation pathway for suspected Cushing’s syndrome + cause?

Answer 8

1 - Overnight dexamethasone test
2 - Plasma ACTH
3a - if ACTH suppressed then Adrenal CT (adrenal cause indicated)
3b - if ACTH not suppressed then Pituitary MRI (non-adrenal cause indicated)