2025 Proffered Presentations
S026: MRI NEGATIVE CUSHING'S DISEASE: SUBTOTAL GLAND RESECTION VERSUS GROSS TOTAL RESECTION TO PRESERVE PITUITARY GLAND FUNCTION
Sandhya R Palit, MBBS; Yuki Shinya, MD, PhD; Dana Erickson, MD; Irina Bancos, MD; Justine S Henderson, PAC; Sukwoo Hong, MD; Jamie J Van Gompel, MD; Mayo Clinic
Introduction: Pre-operative imaging often fails to localize corticotrophin-secreting micro-adenomas, leading to the diagnosis of "MRI-negative Cushing's Disease (CD)." The primary treatment approach is gross total resection (GTR) via either adenomectomy or hemi hypophysectomy. Achieving complete remission in MRI-negative CD is challenging, with remission rates reported to be around 50%, even after confirmation via inferior petrosal sampling. This retrospective study aimed to compare the post-operative outcomes of subtotal gland resection (STGR) versus standard resection of tumor in MRI-negative CD patients undergoing endonasal transsphenoidal surgery (ETS).
Methods: This multi-institutional retrospective cohort study analyzed 214 consecutive patients who underwent ETS for CD between 2012 and 2023. Both MRI-negative and MRI-positive CD patients were included. Pre- and post-operative endocrine functions and surgical outcomes were compared. SGTR was defined as the removal of 75% of the normal pituitary gland, regardless of intraoperative tumor identification. The GTR group included patients who underwent either adenomectomy or hemi hypophysectomy. The primary outcome was post-operative endocrine function, while secondary outcomes included surgical results. Statistical analyses were performed using t-tests, chi-square tests, and Mann-Whitney’s tests with a significance level of p < 0.05.
Results: MRI-positive CD patients had a higher incidence of tumor recurrence (23% vs. 9%; p = 0.001) compared to MRI-negative patients (Table 1). MRI-negative patients were more likely to undergo endoscopic ETS (79% vs. 49%). Pearson’s Correlation Matrix (Figure 1) revealed a weak positive correlation between the MRI status and surgical method (r = 0.18). No significant correlation was observed between other variable pairs.
STGR patients were significantly more likely to undergo endoscopic ETS than standard surgery patients (100% vs. 65%; p = 0.026, Table 2). There was a significant difference in the incidence of intraoperative CSF leaks (p = 0.013, Table 3), with STGR patients having a higher rate (54% vs. 10%). Only one STGR patient required repeated surgery for tumor recurrence, compared to five standard surgery patients. Overall, a remission rate of 75% was observed. When stratified by type of surgeries performed, GTR patients exhibited a remission rate of 65% (n=20, Table 3), while STGR patients had a higher remission rate of 85% (n=13, p = 0.204; Table 3). However, there were no significant differences in other outcomes such as post-operative endocrine function, length of stay, operation time, neurosurgical complications, endocrine remission rates or long-term outcomes.
Conclusion: Our study demonstrates that STGR is a viable option for MRI-negative CD. While STGR may be associated with a higher rate of intraoperative CSF leaks, the post-operative endocrine outcomes are comparable. Additionally, STGR offers the potential to reduce the risk of recurrence and the need for reintervention.
FIGURE 1: Pearson’s Correlation Matrix. Grey box represents the weak positive correlation between the MRI Status and Surgery Method with r = 0.18
