Cushing's

Question 1

What is Cushing’s Syndrome?

Answer 1

Symptoms from exposure to XS cortisol.

Question 2

What is Cushing’s Disease?

Answer 2

XS cortisol from overstimulation of Adrenal Glands by ACTH.

Question 3

Common Causes of Cushing’s Syndrome?

Answer 3

Cushing’s Disease: ACTH secreting pituitary tumor
Adrenal Tumour = XS Cortisol secretion
Metastases e.g. small cell lung cancer
Iatrogenic e.g. XS corticosteroid use

Question 4

Common symptoms of Cushing’s Syndrome?

Answer 4

Weight Gain, mood change (irritability), Hypertension, Fatigue, Poor concentration/memory

Question 5

Common examination signs of Cushing’s Syndrome?

Answer 5

Moon face, thick skin, easy bruising, limb weakness, purple abdominal striae

Question 6

Investigations for Cushing’s?

Answer 6

1) Cortisol Levels (24 hr urinary + midnight salivary)
2) Dexamethasone Suppression Test (Cortisol + Plasma ACTH) - differentiate cause
3) Inferior petrosal sinus sampling - if XS ACTH is produced by pituitary?
4) FBC, U+Es + pituitary MRI/Adrenal imaging

Question 7

Dexamethasone Suppression Test protocol + findings?

Answer 7

1st line = Overnight
2nd line = 48h high dose
Cushing’s Syndrome - High Cortisol, None/Low ACTH
Acute Cushing’s Disease - Suppressed Cortisol (high dose), Normal/High ACTH.
Adrenal Tumour - High Cortisol, Low ACTH.

Question 8

Blood Results?

Answer 8

FBC - Reduced lymphocytes

U+E - Triad: Hypernatraemia, Hypokalaemia, Low bicarb

Question 9

Management of Cushing’s Syndrome?

Answer 9

Manage underlying cause.
Iatrogenic: slowly withdraw medication
Cushing’s disease: Trans-sphenoidal removal of tumour
Adrenal Adenoma/Carcinoma: Adrenalectomy (radio/chemotherapy follow up if carcinoma).