SAT-LB075 Pituitary Function after Surgery for Non-Functioning Macroadenoma: A Tertiary Single Center Retrospective Cohort

Abstract

Introduction: Non-functional pituitary adenomas (NFPA) represent the second most frequent cause of pituitary tumors after prolactinomas. For those patients that harbor a macroadenoma, surgery is indicated in case of visual function disturbances, risk for future optic nerve or chiasm compression, and tumor progression during follow-up. Hypopituitarism, in this context, is only a relative indication for surgery and the available data regarding postoperative hormonal outcomes are inconsistent. The aim of this study was to evaluate the impact of transphenoidal surgery on pituitary function. Methods: We retrospectively analyzed data from 350 patients having had pituitary surgery in a tertiary center, from March 2004 to January 2018, and included 137 non-functioning or gonadotroph adenomas, on the basis of histology reports. There were 40.9% males and 59.1% females, with a mean age of 60 years old at the time of surgery. For 89.9% of patients, indication for surgery was based on visual impact or risk. Mean tumor diameter was 24.8 mm. Patients were operated on with a microscopic trans-septal transsphenoidal approach, by the same experienced surgeon. Hormonal evaluation data were retrieved and patients were classified as normal or deficient, by axis. Pituitary magnetic resonance imaging, before and after surgery, was also analyzed, and the average of the three diameters was calculated. Results: In our cohort, new insufficiencies were observed in 5.1% of patients for the GH axis, 9.2% of patients for the ACTH axis, 8.3% for the FSH/LH axis, and 1.6% for the TSH axis. Among patients with hyperprolactinemia prior to surgery, 71.4% normalized prolactin values postoperatively. Recovery of preoperative insufficiencies was observed in 45.5%, 15.4%, 35.7% and 30.4% for the GH, ACTH, FSH/LH and TSH axis respectively. Logistic regression analysis showed that patients with the smallest decrease in tumor size where at higher risk for developing new insufficiencies after surgery (odds ratio: 11.37, 95% CI: 1.13-114,96) and that male sex was associated with a higher chance of postoperative hormonal recovery (odds ratio: 2.74, 95% CI: 1.11-6.78). Conclusion: Pituitary insufficiency is restored in more than one third of patients after surgery for NFPAs, whereas, new deficiencies appear in less than 10% of patients with previously normal function, with ACTH axis being the most fragile and TSH axis being the most resistant to damage. Poor postoperative results, in terms of volume decrease, are associated with higher risk of new deficiencies. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. s presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.