Intraosseous schwannoma of the mobile spine: a report of twenty cases.

Purpose: To clarify the clinical features, surgical strategies, and outcomes of intraosseous schwannoma (IOS) of the mobile spine.

Methods: We retrospectively reviewed patients with primary benign spinal schwannoma who underwent surgery in our orthopedic department.

Results: A total of 101 patients with primary benign schwannoma located in the mobile spine underwent surgery in our orthopedic department from 2005 to 2015. Twenty-five patients presented with aggressive features. Twenty patients were regularly followed up, twelve with lesions in the cervical spine, six with lesions in the thoracic region, and two with lesions in the lumbar spine. Preoperative CT-guided biopsy was performed in fourteen cases; the accuracy of diagnosis was 100%, and IOS is not histologically different from conventional schwannoma. The computed tomography (CT) scan revealed expansile and osteolytic bone destruction in all these cases, with six patients having pathological fracture. On T2-weighted magnetic resonance imaging, the lobulated schwannomas showed heterogeneous signal intensity and significant heterogeneous enhancement on post-contrast images. Gross total resection was performed in seventeen patients and subtotal resection in three. Tumor-involved nerve roots resection were documented to decrease local recurrence in fourteen cases. The visual analog scale score decreased from 5.66 ± 1.79 preoperatively to 1.16 ± 1.77 at the final follow-up. No local recurrence was noticed at the final follow-up.

Conclusion: CT-guided biopsy is effective for the preoperative diagnosis of spinal IOS. Total resection is the optimal treatment for IOS, whereas subtotal resection could be an alternative choice for high-risk cases. These slides can be retrieved under electronic supplementary material.