15% of primary CNS tumors are intraspinal (the intracranial: spinal CNS ratio for astrocytoma is 10:1; for ependymomas it`s 3-20:1). Most primary spinal tumors are benign (unlike the case with intracranial tumors). Most present by compression rather than invasion.
Types of spinal tumors may be classified in 3 groups. Although metastases may be found in each category, they are usually extradural.
1.
Extradural (55%): arise outside cord in vertebral bodies or epidural tissues
A.Metastatic: comprise the majority of extradural tumors
B.
Primary spinal tumors
2.Intradural extramedullary (40%): arise in leptomeninges or roots
A.Meningiomas
B.Neurofibriomas
C.Schwannomas
D.Miscellaneous
3.Intramedullary spinal cord tumors (5%): arise in spinal cord substances.
Invade and destroy tracts and gray matter
A.Astrocytomas
B.Ependymoma
C.Miscellaneous
Our case series are reviewed and discussed.
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