<prompt> A patient with cushinoid features presents with hemoptysis: he shows no response to dexamethasone supression test; most likely diagnosis here IsAdrenal hyperplasiaAdrenal adenomaCa lung with ectopic ACTH productionPituitary microadenoma  <response>: The dexamethasone suppression test DST is used to assess adrenal gland function by measuring how coisol levels change in response to an injection of dexamethasone. It is typically used to diagnose Cushings syndrome. Dexamethasone suppression test measures whether adrenocoicotrophic hormone ACTH secretion by the pituitary can be suppressed. An abnormal response or no response to the low-dose test may mean that you have abnormal release of coisol Cushing syndrome. This could be due to: Tumor in the body that produces ACTH ectopic cushing syndrome Ref - 