The left and middle photos are those on presentation, while the photo on the right is post-surgery.
A middle-aged woman presented with worsening glycaemic control. On examination, she was noted to have Cushingoid features:
- Moon face
- Truncal obesity, relatively thin arms and legs
- Wasting of limbs, bruising and proximal muscle weakness
- Buffalo hump
- Thinning of skin and purple striae over upper arms, thighs and abdomen
Other classical signs of Cushing’s syndrome
- Pigmentation (in ACTH-dependent Cushing’s)
Diagnostic workup
- Basal morning cortisol to exclude iatrogenic Cushing’s due to exogenous steroids
- Basal 10pm cortisol to look for loss of diurnal rhythm
- Screening tests for Cushing’s syndrome:
- 1mg overnight dexamethasone suppression test for screening (normal suppression <50 nmol/L)
- or 24 hour urine for free cortisol
- Confirmatory test with 48-hour low dose dexamethasone suppression test (normal suppression <50 nmol/L)
- Basal ACTH level to differentiate between adrenal cause (low ACTH) and ACTH-dependent Cushing’s syndrome (normal or high ACTH)
- High dose dexamethasone suppression test and corticotrophin releasing factor stimulation test to differentiate between Cushing’s disease (pituitary cause) and ectopic ACTH
- In ACTH-dependent Cushing’s syndrome:
- MRI of pituitary gland in ACTH-dependent Cushing’s syndrome to look for pituitary adenoma
- Inferior petrosal sinus sampling for ACTH to confirm and localize ACTH-producing pituitary adenoma
- Search for underlying malignancy if suspected ectopic ACTH
- In ACTH-independent Cushing’s syndrome:
- CT or MRI adrenals in ACTH-independent Cushing’s syndrome
Other important investigations
Actively look for other possible complications of Cushing’s syndrome:
- Hypertension
- Glucose intolerance
- Hypokalaemia
- Osteoporosis
- Opportunistic infection
- Mental disturbances including irritability, depression and psychosis
Management
- Trans-sphenoidal surgery for pituitary Cushing’s disease
- Adrenalectomy for adrenal Cushing’s
- Medical therapy including metyrapone and ketoconazole