Disease Remission and Surgical Outcomes of Endoscopic Transsphenoidal Surgery for Cushing Disease: A Single Center Experience

Abstract

Introduction: Transsphenoidal surgery is the primary treatment for patients with Cushing disease (CD). This study assessed the surgical and endocrinologic outcomes of patients with CD following endoscopic pituitary surgery using strict biochemical criteria to guide surveillance in patients not achieving early remission.

Methods: The medical records of all patients with CD who underwent endoscopic transsphenoidal surgery at a single institution between 2004 and 2025 were reviewed. Remission was defined as a fasting serum cortisol level <50 nmol/L (1.8 μg/dL) either basal or after 1 mg dexamethasone.

Results: A total of 125 patients were diagnosed with CD and had a primary endoscopic transsphenoidal surgery during the study period (median age 48 years [range: 14-79 years; M:F 93:32). Fifty-seven patients (45.6%) had a microadenoma, 41 (32.8%) had a macroadenoma, and 26 (20.8%) had no demonstrable focal lesion on pituitary magnetic resonance imaging (MRI) (MRI-negative CD). The median length of follow-up was 3.1 years (range: 1 month to 16.7 years). Initial remission rates 3 months after surgery were: 72.0% for patients with MRI-negative CD, 77.2% for microadenomas, and 48.7% for macroadenomas. Age, male sex, MRI-negative, and single operation were predictors of remission. Patients who achieved remission at 3 months were significantly more likely to be in remission at last follow-up after accounting for patient and tumor characteristics. The 5-year recurrence rate following remission was 6.9%.

Conclusion: Endoscopic transsphenoidal surgery is an effective first-line treatment for patients with CD but a significant minority will relapse. Close biochemical surveillance of patients who fail to achieve remission may support the use of early adjuvant radiotherapy.

Keywords: Cushing disease; Endoscopic transsphenoidal surgery; Remission.