[Test of pituitary adrenal restraining with IV dexamethasone in the diagnosis of Cushing's syndrome (author's transl)].

The authors report a pituitary adrenal retraining test, using a 4 h IV infusion of dexamethasone phosphate (4 mg). Plasma cortisol is measured before and at the end of the infusion. The results allow a good discrimination between Cushing's disease (bilateral adrenal hyperplasia : 9 cases) and Cushing's syndrome of tumorous origin (adrenal tumors 7 cases, ectopic ACTH syndrome 3 cases, hypophyseal adrenomas 2 cases), only bilateral adrenal hyperplasia cases are lowering significantly.