Endocrine Abstracts

JOINT2474

Background: This is service evaluation aimed to assess the remission rate against published literature of patients with confirmed diagnosis of Cushing’s disease undergoing endoscopic endonasal pituitary surgery at a regional tertiary centre in the UK.

Methods: A cohort of 29 patients [19 females (65.5%) and 10 males (34.5%), aged 24–68 years] who underwent endoscopic surgical treatment for Cushing’s disease at Southampton General Hospital (Southampton, UK) between 2016 and 2024 were included in this study. Demographics, clinical characteristics, preoperative diagnostic workup, and surgical outcomes were analysed. The confirmatory diagnostic tests employed included overnight (ODST) and low dexamethasone (LDDST) suppression tests (100%), pituitary MRI with contrast (100%), urinary free cortisol (100%), midnight salivary cortisol series (89%), inferior petrosal sinus sampling (31%, those with no visible adenoma on MRI or size <6mm), and methionine positron emission tomography (MET-PET) in cases of persistent or recurrent disease (20%).

Results: Preoperatively, 31% (9/29) of patients had type 2 diabetes mellitus, and 58% (17/29) were obese (BMI ≥ 30). MRI findings revealed macroadenomas in 31% (9/29) of patients and microadenomas in 69% (20/29). The overall remission rate was 82.8% (24/29), with early remission (postoperative morning cortisol < 55 nmol/lwithin one week) achieved in 51.7% (15/29) of patients. Delayed remission occurred in 31% (9/29); defined as subsequent normalising of urinary free cortisol and salivary cortisol level, or ongoing need for patients’ glucocorticoids replacement. Persistent disease was observed in 17.2% (5/29) of patients. Remission rate was highest for microadenomas (90%, 18/20) compared to macroadenomas (55.5%, 5/9). Of those with macroadenomas, 33.3% (3/9) achieved early remission, 22.2% (2/9) had delayed remission, and 44.4% (4/9) with persistent disease. Cavernous sinus involvement was present in 31% (9/29) of patients and was associated with a lower remission rate [55.5% (5/9)]. Histology confirmed the diagnosis of corticotroph adenoma in 86.2% (25/29) of patients, with one case of ACTH staining gangliocytoma (3.4%, 1/29) and four cases of Crooke’s hyaline changes (13.8%, 4/29). Of the Crooke’s hyaline change cases, two had macroadenomas, one had delayed remission, and one had persistent disease, while all patients with microadenomas and Crooke’s changes achieved early remission.

Conclusion: Endoscopic surgery for Cushing’s disease at our centre yielded a favourable remission rate of 82.8%, with early remission occurring in over half of the patients. Adenoma size and cavernous sinus involvement were significant predictors of remission, with smaller microadenomas and the absence of cavernous sinus involvement associated with better outcomes.