Cavernous sinus sampling in patients with adrenocorticotrophic hormone—dependent Cushing's syndrome with emphasis on inter- and intracavernous adrenocorticotrophic hormone gradients

These results suggest that 1) cavernous sinus sampling without CRH administration can demonstrate hypersecretion of ACTH from the pituitary gland with a high diagnostic accuracy; 2) intercavernous gradients will indicate the correct lateralization in laterally localized microadenomas; and 3) sampling should be performed from the posterior portion of the cavernous sinus.