The surgical management of Cushing disease: a case series from a Canadian tertiary center

To evaluate remission, recurrence, and complication rates following endoscopic transsphenoidal surgery (ETSS) for Cushing disease (CD) at a Canadian tertiary center, and assess concordance of preoperative cerebral MRI and inferior petrosal sinus sampling (IPSS) with intraoperative adenoma laterality.

We retrospectively reviewed 92 patients with confirmed CD who underwent ETSS by a single neurosurgeon between August 2007 and May 2025. Outcomes included biochemical remission, recurrence, and complications. We assessed the concordance of preoperative MRI and IPSS with intraoperative tumor localization.

The cohort included 92 patients (mean age 46.6 ± 15.0 years; 77% female) with a median follow-up of 18.3 months (IQR 6.4-44.9). Preoperative MRI identified a microadenoma in 63 cases, macroadenoma in 17, and was negative in 12. Remission was achieved in 76.7% (86.4% early ≤6 months), with 7.9% experiencing recurrence after a median of 13.2 months. Complications included arginine vasopressin deficiency (AVPD) in 43.5% of the cohort (persistent >6 months in 10.2%), hypothyroidism in 14.1%, syndrome of inappropriate antidiuretic hormone secretion (SIADH) in 5.4%, and cerebrospinal fluid (CSF) leak in 3.3%. Intraoperatively, 78.8% of microadenomas were in the posterior adenohypophysis, and 27.4% exhibited multifocal distribution. Concordance of adenoma laterality was 56.5% for MRI and 41.7% for IPSS, with no statistically significant difference.

ETSS achieved high remission with low morbidity in CD. Frequent posterior and multifocal adenomas in the adenohypophysis support systematic pituitary exploration. Localization remains challenging, with limited concordance using MRI and IPSS, highlighting the need for cautious interpretation in surgical planning.