Planning of Surgical Management of Spinal Schwannomas

Background: Intradural tumors of the spine are usually benign and carry a good prognosis, if they are diagnosed and removed early. Schwannomas make up almost one-third of primary spinal neoplasms. Spinal schwannomas are typically intradural-extramedullary neoplasms thought to be arisen from Schwann cells or their progenitors, which occur proportionally throughout the spinal canal. Objective: Evaluation of twelve consecutive cases of surgically resected spinal schwannomas. Patients and Methods: The first author has operated on twelve consecutive cases of spinal schwannomas at two different centers in KSA over seven years (2007-2014), seven cases at KASH (Taif) and five cases at KSMH (Tabouk). Full MRI craniospinal survey. CT-3D (reformatted image) study for surgical area of concern with accurate preoperative panning for extent of bony resection to avoid iatrogenic spinal instability. Stick on the preoperative plan as much as possible. Immediate postoperative imaging with MRI and CT-3D to evaluate the mass resection, the extent of bony removal, evaluation of the preoperative planning and spinal stability. The final diagnosis was established by immunohistochemical study. Results: We treated twelve spinal schwannomas seven females (58%) and five males (42%). The age interval was 20-59 years. The mean age was 43.3. The tumor was located in the lumbar region in six patients (50%), the thoracic region in three patients (25%), and the cervical region in another three patients (25%). The most frequent complaints included back pain, neck pain, radiculopathy, myelopathy, motor weakness, and voiding difficulty. The onset of the symptoms ranged from 2 weeks to 16 months. The motor functions were evaluated and documented. Follow-ups from 18 to 44 months showed that the symptoms and signs had significantly improved, and no complication of surgery or spinal abnormality occurred in any of the patients that necessitated further spinal intervention or fusion except one case with irrelevant indication. None of our patients presented with clinical deterioration and none of them died. However, one case (8.3%) showed radiological recurrence after thirty eight months. The location of all schwannomas were intradural extramedullary. Conclusion: the spine surgeon should always keep in mind that in the differential diagnosis of neck or low back pain, intradural spine tumors are included and that despite complete resection, these benign extramedullary tumors present a continued risk of recurrence. We also suggest that a wide laminectomy may cause iatrogenic instability and necessitate spinal fusion. Therefore, adequate preoperative planning for extent of bony resection for each case may obviate the need for spinal fusion.