How do you diagnose cushings,”Low dexamethasome suppression-Normal finding is cortisol suppression24 hour urinary free cortisol level-Abnormal finding is elevated cortisolMeasure ACTH-If low –> Adrenal tumor or hyperplasia -If high –> High dose dexa or CRH stimulation testHig-dose dexa suppression-Suppression indicates pituitary pathology-No suppression indicates ectopic ACTH secretionCRH stimulation test-If ACTH increases, its pituitary-If ACTH DN increase
its ectopic”