Cystic spinal schwannomas: A short series of six cases. Can we predict them preoperatively?

BACKGROUND: Spinal schwannomas are benign tumors arising from the spinal nerve root sheaths and are the commonest intradural extramedullary spinal tumors. Though cystic changes in schwannomas are well described, predominantly cystic schwannomas are uncommon lesions and form a different spectrum of conditions as compared with the commonly seen intradural extramedullary solid lesions. CASE DESCRIPTION: We present a case series of six patients with spinal intradural extramedullary cystic schwannomas. Two patients had uniloculated cystic schwannomas, two patients had multi-loculated cystic lesions with thick walls and intralesional septations, and two patients had giant cystic schwannomas, one of which had an extradural extension. We report two cases in which preoperative radiological dilemma was encountered and discuss the differential diagnoses of this uncommon entity. CONCLUSION: Cystic spinal schwannomas may be confused with other cystic lesions in the spine, differentiating them preoperatively is important and in this regard, contrast-enhanced magnetic resonance imaging plays a vital role. Frozen section histopathology should be used to identify them at surgery. It is important to detect these lesions at surgery, as total excision is possible and almost always results in good long-term neurological outcome.