Endocrinology

Question 1

Cushing’s Syndrome vs Cushing’s Disease

Answer 1

CS: used to refer to the signs and symptoms that develop after prolonged abnormal elevation of cortisol
CD: the specific condition where a pituitary adenoma secretes excessive ACTH.
CD causes a CS but CS is not always caused by CD

Question 2

Cushing’s Syndrome Features

Answer 2

• Round in the middle with thin limbs: Round ‘moon’ face, central obesity, abdominal striae, Buffalo Hump, Proximal limb muscle wasting.
• High levels of stress hormone: Hypertension, Cardiac hypertrophy, Hyperglycaemia (T2DM), Depression, Insomnia
• Extra effects: Osteoporosis, Easy bruising and poor skin healing

Question 3

4 Causes of Cushing’s syndrome

Answer 3

• Exogenous steroids (in patients on long term high dose steroid medications)
• Cushing’s Disease
• Adrenal Adenoma (hormone secreting adrenal tumour)
• Paraneoplastic Cushing’s

Question 4

Diagnosing Cushing’s Syndrome

Answer 4

1. Dexamethasone suppression test (low dose(1mg) first, if abnormal, then do high dose(8mg) to find cause)

Pituitary adenoma: cortisol suppressed, ACTH suppressed
Adrenal adenoma: cortisol not suppressed, ACTH suppressed
Ectopic ACTH: neither suppressed

2. 24hr urinary free cortisol

Question 5

Cushing’s treatment

Answer 5

Treat underlying cause

- eg removal of tumour.