2025 Proffered Presentations
S004: BMI, TUMOR SIZE, AND HORMONE PROFILES: KEY DIFFERENCES OF INFRASELLAR VS. SUPRASELLAR PITUITARY TUMOR EXTENSION
David Gomez, BS; Ishan Shah, BS; Kevin G Liu, BS; Apurva Prasad, BA; William Zeng, BS; Timothy Dawson II, BS; David J Cote, MD, PhD; Robert G Briggs, MD; Gabriel Zada, MD, MS; Department of Neurological Surgery, Keck School of Medicine of USC
Introduction: Pituitary tumor growth patterns affect clinical presentation and surgical outcomes, and are associated with various pituitary adenoma subtypes. This study aims to investigate further the differences in clinical and pathological characteristics for patients with infrasellar adenoma invasion compared to suprasellar adenoma extension.
Methods: We conducted a retrospective analysis of our prospectively maintained patient data of 655 pituitary tumor patients at one private surgical center and one public safety net hospital within our institution. Of these, 435 patients with either infrasellar (n=44) or suprasellar (n=391) invasion were analyzed. Clinical data, radiographic findings, laboratory results, and surgical outcomes were compared using descriptive statistics.
Results: Patients with infrasellar invasion had significantly higher mean BMI (33.20 vs 30.24, p=0.02) and pre-operative IGF-1 levels (446.7 vs 181.2, p<0.001) compared to those with suprasellar extension. Suprasellar extension was associated with larger tumor diameter (25.86mm vs 22.07mm, p=0.02) and longer inpatient stay (3.67 vs 2.47 days, p<0.001). Infrasellar invasion was associated with lower rates of visual field deficits (OR: 0.102, p<0.001) and higher rates of pre-operative acromegaly (40.91% vs 7.16%, OR: 8.975, p<0.001). Hormone staining patterns differed significantly, with infrasellar tumors more likely to be prolactin-positive (45.45% vs 17.65%, OR: 3.889, p<0.001), GH-positive (45.45% vs 11.76%, OR 6.25, p<0.001), and ACTH-positive (27.27% vs 14.07%, OR 2.291, p=0.03). Alpha-subunit staining was less common in infrasellar tumors (15.91% vs 40.15%, OR 0.283, p=0.002). No significant differences were observed in age, pre-operative prolactin, cortisol, or growth hormone levels, Ki-67 index, post-operative sodium levels, gender, pre-operative cranial nerve palsy, Cushing's disease or pituitary apoplexy, cavernous sinus invasion, tumor consistency, or extent of resection between the two groups.
Conclusion: This study reveals significant differences in PA subtypes and several key outcomes in patients with infrasellar versus suprasellar extrasellar growth. Higher BMI and elevated IGF-1 levels are associated with infrasellar invasion, revealing possible clinical risk factors. Suprasellar extension, in contrast, is linked to larger tumors and visual field deficits from pressure on the optic apparatus. Despite clinical and radiographic differences, surgical results, including extent of resection, are comparable between the two groups. Future studies should explore the causal drivers of variant extrasellar growth patterns and hormonal relationships in pituitary adenomas.