2025 Proffered Presentations
S024: PRESENTATION AND TRANSSPHENOIDAL SURGERY OUTCOMES AT A NEWLY ESTABLISHED CENTER OF EXCELLENCE IN PATIENTS WITH ACROMEGALY
Margaret E Allen, BS; Samon G Tavakoli, MD; Nathan T Zwagerman, MD; Stephanie K Cheok, MD; Adriana G Ioachimescu, MD, PhD; Medical College of Wisconsin
Acromegaly is characterized by insidious development of clinical manifestations of growth hormone excess such as acral enlargement and coarsening of facial features, as well as comorbidities common in general population (hypertension, hyperglycemia, arthritis, sleep apnea, carpal tunnel syndrome). At diagnosis (achieved in average 5 years after onset of symptoms), most growth hormone (GH)-secreting pituitary adenomas are macroadenomas with various degrees of cavernous sinus invasion. Transsphenoidal resection is the first line treatment, with adjuvant therapy consisting of medications and less frequently radiation for patients with persistent biochemical activity. Surgical remission is inversely proportional with tumor size, Knosp grades of cavernous sinus invasion, and preoperative GH level. Survival is decreased in active acromegaly and normalizes after IGF-1 control. We retrospectively evaluated all patients (N=51, 51% male) operated between 7/2018-2/2024 at a newly established center of excellence for acromegaly by a single skull base trained neurosurgeon with diagnosis confirmed by GH immunostaining. Mean age (SD) at surgery was 48.6 (14.9). Comorbidities included type 2 diabetes mellitus (17.6%), hypertension (33.3%), and hypopituitarism (39.2%). The main presentations of GH-adenomas were: physical changes (61.6%), incidental pituitary mass (15.4%), head mass effects (11.5%), and other (11.56%). GH-incidentaloma patients had brain imaging for cervical spine evaluation (37.5%), head trauma (25%), lightheadedness (12.5%), hearing loss (12.5%), and unilateral weakness (12.5%). Prevalence of tumor-related vision changes and hypopituitarism were higher in males (30.8% and 57.7% respectively) than in females (4.0% and 20.0% respectively, p<0.05 for both). Eleven patients (21.5%) had prior pituitary surgery elsewhere. Mean (SD) tumor diameter was 18.9 (8.6) mm, and 74.8% tumors were macroadenomas. Hyperprolactinemia was noted in 21.6% cases preoperatively. The mean (SD) follow-up time was 31.9 (20.8) months. Biochemical remission (defined as normal IGF-1 between 3-12 months postoperatively without medical or radiation therapy) occurred in 22/50 (44.0%) patients with follow-up information. Of the 11 patients whose primary surgery was elsewhere, 3 (27.3%) achieved postoperative remission. Four patients (7.8%) underwent reoperation and 3 (5.9%) radiation after their surgery at this center. At last follow-up, 37 (74%) patients were in remission as a result of multimodality therapy including medical treatment. No patients had biochemical recurrence. Our findings confirm recent studies indicating that GH-secreting adenomas can be incidentally detected in a significant proportion of patients, highlighting the importance of IGF-1 screening in these cases. One limitation of our study is using IGF-1 level as a single parameter to determine postoperative remission status due to lack of information regarding random or glucose-suppressed GH levels postoperatively in many patients. The Covid-19 pandemic was contributory to loss to follow up in some patients. Another limitation is lack of information regarding somatotroph adenoma granulation status in most patients. Neuropathological pituitary adenoma evaluation was standardized per WHO guidelines at our institution in 2022. Endocrine evaluation was standardized in 2023 after a pituitary endocrinologist joined the center. Our study demonstrates the importance of a tertiary pituitary center in acromegaly which can offer improved outcomes by multimodality therapy and long-term surveillance.