Endoscopic Endonasal Approach for Rare Skull Base Pathologies: Insights from a Neurosurgical Perspective

Background: Endoscopic endonasal approach (EEA) has become a well- established approach for skull base pathologies, providing a minimally invasive corridor to access various lesions. While the technique has been extensively studied for common skull base tumors, data on extremely rare pathologies remain limited. Our study aims to present our experience with rare skull base lesions managed via the endoscopic endonasal approach, highlighting the challenges associated with preoperative diagnosis, intraoperative decision-making, and surgical strategy modifications. Methods: A retrospective analysis was conducted on patients who underwent endoscopic endonasal surgery at the tertiary center up to January 2025. Among 6,225 endoscopic endonasal procedures performed, 41 patients with exceptionally rare skull base pathologies were identified. Each tumor type was separately evaluated for differences in resection rates, complication rates, and recurrence patterns. Results: These included 6 pituitary pituicytomas, 5 plasmacytomas, 5 xanthogranulomas, 4 granular cell tumors, 3 giant cell tumors and others. Gross total resection was achieved in 68% of cases, with subtotal resection in vascular or malignant tumors. Intraoperative challenges included unexpected vascularity and fibrotic adhesions. Postoperative CSF leakage occurred in 7%, and recurrence was observed in 17%, mostly in malignant or partially resected tumors. No intraoperative mortality was recorded. Tailored adjuvant treatments ensured durable disease control in most patients. Conclusions: Even in highly experienced centers, rare skull base pathologies pose unique diagnostic and surgical challenges. The discrepancy between preoperative and intraoperative findings often necessitates real-time strategic adaptations. In these rare cases, for optimizing patient outcomes requires a comprehensive understanding of skull base anatomy, flexibility in surgical planning, readiness for sudden strategy modifications, and a multidisciplinary approach.