Long-term postoperative outcomes of spinal cellular schwannoma: study of 93 consecutive cases

BACKGROUND CONTEXT:Cellular schwannoma (CS) is a rare tumor that accounts for 2.8-5.2% of all benign schwannomas. There is a dearth of up-to-date information on spinal CS in the literature. PURPOSE:The aims of this study were to identify the proportion of CS cases amongst spinal benign schwannoma, describe the clinical features of spinal CS, and identify prognostic factors for local recurrence by analyzing data from 93 consecutive CS cases. STUDY DESIGN:Retrospective review. PATIENT SAMPLE:We analyzed 93 PSGCT screened from 1706 patients with spine CS who were treated at our institute between 2008 to 2021. OUTCOME MEASURES:Demographic, radiographic, operative and post-operative data were recorded and analyzed. METHODS:We compared the clinical features of spinal CS from the cervical, thoracic, lumbar and sacral segments. Prognostic factors for local recurrence-free survival (RFS) were identified by the Kaplan-Meier method. Factors with p ≤ 0.05 in univariate analysis were subjected to multivariate analysis by Cox regression analysis. RESULTS:The proportion of spinal CS in all benign schwannomas was 6.7%. The mean and median follow-up times for the 93 patients in this study were 92.2 and 91.0 months respectively (range 36 to 182 months). Local recurrence was detected in 11 cases, giving an overall recurrence rate of 11.7%, with one patient death. Statistical analysis revealed that tumor size ≥ 5 cm, intralesional resection, and Ki-67 ≥ 5% were independent negative prognostic factors for RFS in spinal CS. CONCLUSIONS:Whenever possible, en bloc resection is recommended for spinal CS. Long-term follow-up should be carried out for patients with tumor size ≥ 5cm and postoperative pathological Ki-67 ≥ 5%.