2026 Poster Presentations
P118: SURGICAL OUTCOMES AND COMPLICATION PROFILES FOLLOWING RESECTION OF SKULL BASE EPIDERMOID CYSTS: META-ANALYSIS
Khushal Gupta, MBBS1; Michael Karsy, MD, PhD, MSc, FAANS, FCNS2; 1Bharat Ratna Late Shri Atal Bihari Vajpayee Memorial Medical College; 2University of Michigan Health
Introduction: Epidermoid cysts of the skull base are rare but surgically demanding lesions. Their benign histology contrasts with the significant morbidity they can cause through compression of cranial nerves and brainstem structures. Complete resection is desirable, yet often limited by adherence to critical neurovascular anatomy. Reported outcomes vary widely across centers, making pooled evidence essential to guide surgical practice.
Methods: We performed a systematic review and single-arm meta-analysis in accordance with PRISMA guidelines. PubMed, Embase, Scopus, and Cochrane Library were searched through July 2025. Studies were eligible if they reported ≥5 patients with skull base epidermoid cysts undergoing surgical resection and provided extractable outcomes. Case reports, purely radiologic series, and duplicate data were excluded. Two independent reviewers screened articles, extracted data, and assessed methodological quality, with consensus resolution for discrepancies. Extracted variables included demographics, tumor location, surgical approach, extent of resection, postoperative complications, recurrence, and mortality. Pooled estimates were generated using random-effects models (DerSimonian–Laird method) with inverse-variance weighting and Freeman–Tukey double arcsine transformation for proportions. Statistical heterogeneity was quantified using τ² and I², and 95% prediction intervals were calculated to reflect between-study variability. Primary outcome was gross total resection (GTR); secondary outcomes included recurrence, complication rates, and mortality.
Results: Ten studies encompassing 411 patients met inclusion. The pooled rate of gross total resection (GTR) was 62% (95% CI: 49–74%), though with considerable heterogeneity (I² = 83.3%), reflecting the technical nuances of these operations. The mortality rate was strikingly low at 1% (95% CI: 0–2%), with no evidence of heterogeneity (I² = 0%), underscoring the relative safety of modern microsurgical techniques. By contrast, the overall complication rate was 22% (95% CI: 9–39%), with high heterogeneity (I² = 88.7%). Complications ranged from transient cranial neuropathies and CSF leaks to meningitis and hydrocephalus, highlighting differences in definitions and reporting across studies. Long-term recurrence was observed in 15% (95% CI: 6–27%), again with high variability (I² = 87.2%). Even after seemingly complete resections, recurrence remained a meaningful long-term concern, emphasizing the importance of continued surveillance.
Conclusion: Surgery for skull base epidermoid cysts is generally safe, with exceptionally low mortality and a reasonable likelihood of achieving GTR. However, the procedure carries a meaningful risk of postoperative complications and a persistent chance of recurrence over time. These findings highlight the balance between aggressive resection and preservation of neurological function. Standardized reporting and prospective multicenter collaborations are needed to clarify best practices and optimize long-term outcomes for this rare but challenging entity.
