Comparison of Surgical Outcomes and Recurrence Rates of Cystic and Solid Vestibular Schwannomas

Objective Cystic vestibular schwannomas (CVSs) are anecdotally believed to have worse clinical and tumor-control outcomes than solid vestibular schwannomas (SVSs); however, no data have been reported to support this belief. In this study, we characterize the clinical outcomes of patients with CVSs versus those with SVSs. Design This is a retrospective review of prospectively collected data. Setting This study is set at single high-volume neurosurgical institute. Participants We queried a database for details on all patients diagnosed with vestibular schwannomas between January 2009 and January 2014. Main Outcome Measures Records were retrospectively reviewed and analyzed using univariate and multivariate analyses to study the differences in clinical outcomes and tumor progression or recurrence. Results Of a total of 112 tumors, 24% (n = 27) were CVSs and 76% (n = 85) were SVSs. Univariate analysis identified the extent of resection, Koos grade, and tumor diameter as significant predictors of recurrence (p ≤ 0.005). However, tumor diameter was the only significant predictor of recurrence in the multivariate analysis (p = 0.007). Cystic change was not a predictor of recurrence in the univariate or multivariate analysis (p ≥ 0.40). Postoperative facial nerve and hearing outcomes were similar for both CVSs and SVSs (p ≥ 0.47). Conclusion Postoperative facial nerve outcome, hearing, tumor progression, and recurrence are similar for patients with CVSs and SVSs. As CVS growth patterns and responses to radiation are unpredictable, we favor microsurgical resection over radiosurgery as the initial treatment. Our data do not support the commonly held belief that cystic tumors behave more aggressively than solid tumors or are associated with increased postoperative facial nerve deficits.