LAUSR

ntradural spinal cord tumors are classified on the basis I of their location in relation to the spinal cord parenchyma. Intramedullary spinal cord tumors (IMSCTs) exist within the spinal cord, while extramedullary spinal cord tumors (EMSCTs) exist outside the spinal cord within the subarachnoid space. Patients typically present with pain (local, radicular), sensory deficits (dysesthesias, numbness, proprioceptive loss), and/or weakness (focal weakness, clumsiness/falls). Diagnosis is typically based on imaging studies, including magnetic resonance imaging (MRI). The two most common types of IMSCTs are astrocytomas and ependymomas. Astrocytomas are diffuse, infiltrating lesions that heterogeneously enhance and can have intratumoral cysts and/or necrosis. Gross total resection is not possible because of the infiltrating nature of these lesions. Ependymomas, alternatively, are typically well circumscribed and may have rostral and/or caudal cysts. Adequate surgical treatment requires the surgeon to find a plane of resection to minimize the risk of recurrence. The two most common EMSCTs are nerve sheath tumors (schwannomas, neurofibromas) and meningiomas. Schwannomas do not involve the nerve root, so they typically can be resected without nerve root sacrifice, unlike neurofibromas, which involve and expand the nerve root. Meningiomas arise from the arachnoid cap cells, may have a dural tail, and can calcify. Imaging characteristics differ, in that nerve sheath tumors more typically show a heterogeneous enhancement pattern on MRI, and meningiomas homogeneously enhance. Both types of lesions widen the subarachnoid space and displace