2025 Poster Presentations
P243: NEGATIVE PITUITARY MRI FINDINGS IN CUSHING'S DISEASE DO NOT LEAD TO INFERIOR RATES OF LONG-TERM REMISSION FOLLOWING TRANSSPHENOIDAL SURGERY-A SINGLE CENTER EXPERIENCE
William Burns; Gurkirat Kholi, MD; Tharan Mungara; Nicolas Contento, MD; Prasanth Romiyo, MD; Rohin Singh, MD; Ismat Shafiq, MBBS; Edward Vates, MD, PhD; URMC
First line treatment for Cushing’s Disease (CD) is transsphenoidal surgery (TSS). However, despite endocrinologic confirmation of CD, MRI findings can be negative in up to half of patients with CD. It is controversial whether outcomes differ between patients with MRI positive CD compared to MRI negative CD. We performed a retrospective analysis of patients with endocrinologic CD treated with transsphenoidal surgery at our institution from 2010-2020. 38 MRI positive CD (74% female) and 20 MRI negative CD (65% female) patients were included in the analysis. Histopathologic confirmation of pituitary corticotroph adenoma was obtained in 96% (N=36) of MRI positive CD patients and 50% (N=10) of MRI negative CD patients (p<0.001). Short-term remission, defined as morning serum cortisol <10 mcg/dL within three months of surgery necessitating glucocorticoid replacement therapy, was achieved in 87% (N=33) of patients with MRI positive CD and 65% (N=13) of patients with MRI negative CD (p=0.05). Recurrence, defined as symptomatic hypercortisolemia after initial remission, occurred in 42% (N=15) of MRI positive CD patients and 23% (N=3) of MRI negative CD patients (p=0.24) after 2.3±1.6 years and 1.3±1.4 years, respectively. Accordingly, long term remission from initial TSS in MRI positive and MRI negative CD patients, after a mean length of follow-up of 6.6±3.5 years, was 55% (N=21) and 50% (N=10), respectively (p=0.71). After additional attempted interventions, including repeat surgery, radiation, adrenalectomy, and/or medication, persistent Cushing’s disease remained in 14% (N=5) of MRI positive CD patients and 10% (N=2) of MRI negative CD patients (p=0.65). When analyzing the entire CD cohort, factors significantly associated with achieving short term remission included positive preoperative MRI findings (p=0.05) and histological confirmation (p=0.05). However, these factors were poor predictors of long-term remission (p=0.71 and p=0.79, respectively). Instead, factors that significantly predicted long-term remission included preoperative serum morning cortisol (19.5±5.8 vs 27.0±17.5 mcg/dL, p=0.02), preoperative midnight salivary cortisol (259.9±138.0 vs 573.0±698.6 ng/dL, p=0.05), and serum morning cortisol obtained around three months postoperatively (10.3±7.2 vs 18.0±18.9 mcg/dL, p=0.05). Factors which approached significance included postoperative day five serum morning cortisol (10.0±11.5 vs 16.0±10.5 mcg/dL, p=0.06), gross total resection (p=0.07), preoperative 24-hour urine free cortisol (90.6±78.0 vs 188.5±253.7 μg/d, p=0.09), postoperative serum ACTH (33.6±28.4 vs 46.4±29 pg/mL, p=0.11), and lack of cavernous sinus invasion (p=0.12). In conclusion, despite a lower short-term remission rate among patients with negative MRI findings following TSS for treatment of CD, rates of long term remission and persistent disease are similar compared to patients with MRI positive CD. Similarly, histological confirmation of a pituitary corticotroph adenoma predicts short-term but not long term remission. Long-term remission is more accurately predicted by pre- and post-operative cortisol levels, the extent of resection, and cavernous sinus invasion. The finding that surgery can successfully induce long-term remission in the absence of histological confirmation or positive MRI findings is a perplexing phenomenon that has similarly been observed in other reports. In addition to laboratory sampling error, one hypothesis for these findings is that surgery may induce postoperative ischemic necrosis of the residual adenoma.