Cystic Schwannoma of the Spine – A Review of Literature and a Report of a Series of 5 Cases

Abstract

Nerve sheath tumors are among the most common intradural spinal tumors , but intraspinal cystic nerve sheath tumors are a rare entity. MR imaging forms the diagnostic modality of choice. We discuss here 5 cases of cystic schwannoma of the spine, of which 4 were at the thoracolumbar junction (D12-L1), and one at D11-D12 level. The patients presented with varying degrees of cord compression symptoms including paresthesia, weakness in the lower limbs and in one patient with paraplegia. The treatment and prognosis of the cystic schwannoma lesion is basically similar to that of the solid schwannomas and includes complete excision of the tumor to prevent recurrence. Ki 67 index provides a reliable prognostic indicator to predict recurrence of a cystic schwannoma after surgical resection. All the patients were treated with en masse excision of tumor. The tumor tissue was assessed for Ki67 index, an index of tumor doubling time, and a reliable indicator of tumor recurrence in subtotal or incomplete removal. All the patients showed improvement in neurological status in the postoperative period. All the patients are on regular follow up and there has been no signs of recurrence yet. Key words: Nerve sheath tumors, cystic schwannoma, diagnosis, treatment, prognosis, Ki 67 index