Cushing's syndrome

Disorder of ↑ cortisol
Etiology Most common endogenous cause: pituitary adenoma
Most common exogenous cause: Corticosteroids
Epidemiology
Clinical presentation - plethoric face
- central obesity
- hypertension
- proximal myopathy
- hirsutism, frontal alopecia
- polycythaemia
Pathogenesis
Diagnostic investigations Dexamethasone suppression test - expect morning cortisol ↑ (>50 nm/L)
Late night salivary cortisol (2300 to midnight) - expect ↑
24h urinary free cortisol - usually require 2-3 samples
Pituitary MRI - for pituitary adenoma
Management Medical management:
> somatostatin analogue (pasireotide),
> a dopamine agonist (cabergoline),
> a steroidogenesis inhibitor (osilodrostat, ketoconazole, OR
> levoketoconazole, metyrapone, mitotane, and etomidate), OR
> glucocorticoid receptor antagonist (mifepristone)

Ddx:

  • PCOS
  • primary psychiatric disorders (although one wonders if it is not the opposite that is true)
  • alcohol excess