Skip to content

Spinal Schwannoma

Summary

  • Benign nerve sheath tumour arising from Schwann cells of spinal nerve roots
  • Typically presents with radicular pain, sensory changes, and/or motor weakness
  • Characteristic imaging findings include a well-circumscribed, enhancing intradural-extramedullary mass1

Pathophysiology

  • Originates from Schwann cells of spinal nerve roots
  • Usually solitary, but can be multiple in neurofibromatosis type 2 (NF2)
  • Slow-growing tumours that compress adjacent neural structures
  • Histologically characterised by Antoni A (cellular) and Antoni B (loose) areas

Demographics

  • Accounts for 30% of primary spinal tumours
  • Most common in adults aged 40-60 years
  • No significant gender predilection
  • Increased incidence in patients with NF2

Diagnosis

  • Clinical presentation:
    • Radicular pain along the affected nerve root
    • Sensory changes in the corresponding dermatome
    • Motor weakness in severe cases
    • Myelopathy if spinal cord compression occurs
  • Physical examination:
    • Neurological deficits corresponding to the affected spinal level
    • Possible signs of myelopathy in advanced cases

Imaging

  • MRI:
    • T1-weighted: isointense to hypointense relative to spinal cord
    • T2-weighted: hyperintense
    • Contrast-enhanced: strong, homogeneous enhancement
    • "Target sign" on axial T2: central hypointensity with peripheral hyperintensity
  • CT:
    • Isodense to hypodense soft tissue mass
    • Possible widening of neural foramen or scalloping of vertebral bodies
  • Plain radiographs:
    • May show widening of neural foramen or scalloping of vertebral bodies in large tumours

panels-1

Treatment

  • Surgical resection is curative. A well-defined, avidly enhancing intradural-extramedullary mass with a "target sign" and neural foraminal ("dumbbell") extension is typical; multiple schwannomas suggest NF2

Differential diagnosis

Differential Diagnosis Differentiating Feature
Meningioma Typically dural-based, often calcified, and enhances homogeneously
Neurofibroma "Target sign" on T2-weighted MRI (central low, peripheral high); dumbbell-shaped neural foramen expansion; may be multiple
Ependymoma Intramedullary location; often with associated syrinx; haemosiderin "cap sign" on SWI
Metastasis Multiple lesions; may show associated bony involvement; more aggressive growth pattern
Herniated disc Typically at disc level; follows disc signal on T2; no contrast enhancement
Spinal arteriovenous malformation Flow voids on MRI; associated cord oedema; serpiginous vessels on surface
Arachnoid cyst No contrast enhancement; CSF signal on all sequences including FLAIR
Epidural abscess Rim-enhancing collection; restricted diffusion in cavity; associated cord compression
Spinal cord lipoma Fat signal on all MRI sequences, no contrast enhancement
Tarlov cyst Occurs along nerve roots, typically in sacral region

  1. Hajikarimloo et al. Preoperative Differentiation of Spinal Schwannoma and Meningioma Using Machine Learning-Based Models: A Systematic Review and Meta-Analysis. 2025. World neurosurgery - Open in new tab. ↩