Cushing's disease

Question 1

what are the electrolyte findings in cushing’s disease?

Answer 1

1. hypernatraemia

2. hypokalaemia

Question 2

what are the general lab findings showing?

Answer 2

1. hyperglycaemia

2. hyperlipidaemia

Question 3

STEP 1 - How is hypercortisolism indicated?

Answer 3

1. increase in 24 urine cortisol

2. rise in cortisol following in low dose dexamethasone suppression

Question 4

STEP 2 - how is primary vs secondary hypercortisolism identified

Answer 4

1. Serum ACTH levels

- if ACTH is high - 2nd cause of hypercortisolism

Question 5

STEP 3 - differentiate between ‘Cushing’s disease’ vs ectopic ACTH

Answer 5

1. High dose dexamethasone suppression test

• cortisol <50% = cushing’s disease
• ectopic = no supression

2. CRH stimulation test
   - ‘cushing’s disease : ACTH and cortisol levels increase more
   - no increase in ACTH or cortisol levels : ectopic ACTH

Question 6

What imaging must be done for primary cause Cushing’s syndrome

Answer 6

primary - CT/MRI of abdomen

Question 7

What imaging must be done for secondary Cushing’s syndrome

Answer 7

CT/MRI of the skill

Question 8

What imaging must be done for ectopic cause Cushing’s syndrome

Answer 8

Chest x ray / CT

Question 9

Tx of primary hypercortisolism

Answer 9

Adrenalectomy

Question 10

Tx of secondary hypercortisolism

Answer 10

Pituitary radiation therapy / surgery