Spinal cord tumors are rare but clinically significant, causing progressive neurological deficits. MRI is the modality of choice for diagnosis, localization, and surgical planning.

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📍 Classification of Spinal Cord Tumors by Location

1. Extradural (most common, ~55%)
   • Metastases, lymphoma, myeloma
   • Nerve sheath tumors (schwannoma, neurofibroma)
   • Meningioma
2. Intradural–Extramedullary (~40%)
   • Meningioma
   • Nerve sheath tumors
   • Drop metastases (from intracranial tumors like medulloblastoma, ependymoma)
3. Intramedullary (~5%)
   • Astrocytoma (Children > adults)
   • Ependymoma (Adults > children)
   • Hemangioblastoma
   • Rare: ganglioglioma, oligodendroglioma

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🔎 MRI Features

General Principles

• T1: tumor hypointense to isointense
• T2: hyperintense
• Post-contrast: variable enhancement
• Cord expansion: intramedullary lesions
• Associated features: syrinx, edema, cysts, hemorrhage

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1. Extradural Tumors

• Most commonly metastases
• MRI: hypointense on T1, hyperintense on T2, variable enhancement
• Vertebral body destruction, soft tissue mass compressing cord

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2. Intradural–Extramedullary Tumors

• Meningioma:
  • Middle-aged women
  • Iso- to hypointense on T1, iso-/hyperintense on T2
  • Homogeneous enhancement, dural tail sign
• Nerve sheath tumors (schwannoma, neurofibroma):
  • Well-defined, eccentric to cord
  • T2 hyperintense, heterogeneous
  • “Target sign” (neurofibroma), cystic degeneration (schwannoma)

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3. Intramedullary Tumors

• Astrocytoma:
  • Pediatric predominance
  • Long-segment involvement, infiltrative, heterogeneous enhancement
• Ependymoma:
  • Adult predominance
  • Central, well-defined, expansile
  • Homogeneous enhancement
  • “Cap sign”: hemosiderin rim on T2/gradient
• Hemangioblastoma:
  • Focal, enhancing nodule with cyst/syrinx
  • Flow voids from feeding vessels

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🧠 Teaching Points

• Location is key: extradural vs intradural–extramedullary vs intramedullary.
• Ependymoma vs astrocytoma:
  • Ependymoma → central, well-circumscribed, cap sign, adults
  • Astrocytoma → eccentric, infiltrative, children
• Always evaluate for skip metastases and CSF seeding (use contrast MRI whole neuraxis).

📊 Comparison of Common Spinal Cord Tumors (MRI Features)

Feature	Meningioma	Schwannoma / Neurofibroma	Ependymoma	Astrocytoma
Location	Intradural–extramedullary	Intradural–extramedullary (eccentric to cord)	Intramedullary (central)	Intramedullary (eccentric)
Age	Middle-aged women	Adults, any age	Adults > children	Children > adults
T1 signal	Iso-/hypointense	Iso-/hypointense	Iso-/hypointense	Iso-/hypointense
T2 signal	Iso- to hyperintense	Hyperintense (may be heterogeneous)	Hyperintense, central	Hyperintense, often heterogeneous
Enhancement	Homogeneous, strong	Variable, often heterogeneous	Homogeneous	Patchy/heterogeneous
Special signs	Dural tail sign	“Target sign” (neurofibroma), cystic changes (schwannoma)	Cap sign (hemosiderin rim), polar cysts, syrinx	Long-segment expansion, infiltrative, syrinx
Cord effect	Compression, displacement	Compression, displacement	Central cord expansion, well-circumscribed	Diffuse cord expansion, poorly defined
CSF seeding	Rare	Rare	May occur (drop metastases)	Rare
Other features	Calcification may be present	May show dumbbell extension through foramina	Most common adult intramedullary tumor	Most common pediatric intramedullary tumor

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🧠 Teaching Nuggets

• Intradural–extramedullary → think meningioma or schwannoma.
• Intramedullary → adults → ependymoma; children → astrocytoma.
• Key MRI signs:
  • Dural tail = meningioma
  • Target sign = neurofibroma
  • Cap sign = ependymoma