Indications and Limitations of Endoscopic Transnasal Surgery for Posterior Fossa Intradural Tumors: Insights from 53 Cases

Introduction: Open craniotomy is the benchmark for intradural posterior fossa tumors, yet endoscopic transnasal surgery (ETS) promises comparable oncologic control with less morbidity. Its exact indications and safety remain debated. Objective: To clarify the role of ETS for these tumors through a single-center series. Methods: We retrospectively reviewed 53 consecutive patients (June 2016 – April 2025). Twenty-nine had pure intradural lesions (IT) and 24 skull-base tumors with intradural extension (SB-IE). All procedures used a transclival route; pituitary transposition or transodontoid extension was added when required. Resection grade and morbidity were assessed from operative notes and postoperative MRI. Results: Histology and brain-stem distribution are shown in [ Fig. 1 ]. Gross, near-total, subtotal (>90%), and partial (