Perioperative cortisol can predict hypothalamus-pituitary-adrenal status in clinically non-functioning pituitary adenomas

Background: Peri-operative steroids are administered routinely to patients with pituitary adenoma undergoing transsphenoidal adenomectomy (TSA). Aim: To evaluate hypothalamic-pituitary-adrenal (HPA) axis before and after programmed endoscopic TSA (E-TSA) in patients with clinically non-functioning pituitary macroadenoma (NFPA). Design: Open prospective. Setting: Tertiary referral hospitals. Patients: Seventy-two consecutive patients (20–87 yr, 37 males). Interventions: Adrenal steroid replacement therapy (ASRT) was given only in patients with hypocortisolism [08:00 h cortisol (F) 90%) selective resection of the adenoma in all, F and clinical picture were checked at day 2. The low-dose (1 µg) ACTH test (LDACTH) was performed at 6 weeks and repeated at 12 months. Results: Hypocortisolism was present pre-operatively in 14 patients (19.4%), persisted post-operatively in all but one, and was detected de novo at the post-operative day 2 control in 6 (10.3%). In all but one the post-operative day 2 basal F and peak F during LDACTH test were concordant. No patient whose F was > 8 µg/dl was treated with ASRT or developed symptoms of adrenal failure during the follow-up (1–11 yr, median 5). Conclusions: HPA function is usually preserved in NFPA and is infrequently impaired after complete tumor removal by E-TSA. The 08:00 h. plasma cortisol evaluation before and 2 days after surgery, using as cut-off the value of 8 µg/dl, allows full evaluation of HPA status. Peri-operative steroid treatment should be given only in patients with hypocortisolism.