[Pituitary microadenoma of Cushing's disease. Course following transsphenoidal excision. Four cases (author's...

Transsphenoidal microsurgery was performed in four patients with a pituitary microadenoma who presented Cushing's disease. Preoperative features were the following: 1) Clinical and laboratory signs of hypercortisolism 2) No radiological evidence of an adrenal tumor 3) Normal or increased ACTH plasma levels 4) Sellar tomograms suggesting the presence of a pituitary microadenoma in only one case. Postoperative outcome after 3 to 30 months follow-up showed persistence or even improved reactivity of the various pituitary functions and especially the early occurence of corticotropin deficiency in all 4 patients. This isolated deficiency regressed spontaneously after 6 and 12 months (2/4 cases). Twenty-four hour studies of ACTH and cortisol profiles and dexamethasone suppression as well as response to metyrapone confirmed the resumption of physiological corticotropin regulation.