Management of skull base meningiomas with extracranial extension: resection, recurrence, and prognostic factors.

PURPOSE

To assess clinical, radiographic, surgical, and pathological factors affecting outcomes in patients with skull-base meningiomas (SBMs) with extracranial extension, focusing on extent of resection (EOR), recurrence rates, postoperative complications, and skull-base (SB) reconstruction strategies.

METHODS

We conducted a retrospective cohort study of 101 patients with SBMs and transcranial extension treated surgically between 1993 and 2024. Tumors were categorized by the Irish classification (Zones I-III). We collected demographics, imaging, surgical details (approach and EOR), pathology (WHO grade, brain invasion, cranial-nerve involvement), and adjuvant therapy. Primary outcomes included gross total resection (GTR) rate, postoperative complications, progression-free survival (PFS), and overall survival (OS). Multivariable Cox-regression and Firth's-logistic regression identified independent predictors.

RESULTS

Zone I was most common (47%), with orbital (41%) and infratemporal-fossa (18%) extension. GTR was achieved in 61.4% overall-highest in Zone I (70.2%). Cerebrospinal-fluid leaks occurred in 8% (highest in Zone III, 27%), and wound infections in 2.9%, none requiring debridement. Tumor recurrence occurred in 40%; subtotal resection (STR; hazard ratio [HR] 2.73, p = 0.014), WHO grade III (HR 27.3, p = 0.003), cranial-nerve dysfunction, and brain invasion independently predicted reduced PFS. STR, Simpson grade > 1, cavernous-sinus invasion, and brain invasion predicted worse OS. Multidisciplinary SB reconstruction using autologous grafts and prosthetic materials (PEEK, titanium mesh) was essential to minimize morbidity.

CONCLUSION

SBMs with extracranial extension present complex surgical challenges. EOR, tumor histology, and invasion of critical structures significantly influence recurrence and survival. Tailored surgical planning by zone and comprehensive SB reconstruction are critical to optimize outcomes and reduce postoperative morbidity.