Spinal Tumors

Question 1

Differential diagnoses for intramedullary spinal lesions “I HEAL”

Answer 1

1. Inflammatory/demyelinating
2. Hemangioblastoma
3. Ependymoma
4. Astrocytoma
5. Lipoma, dermoid cyst

Question 2

Imaging features of spinal ependymoma (intramedullary!)

Answer 2

1. Most common intramedullary spinal cord tumor in adults.
2. Well-defined, centrally located in the cord as arises from the ependymal lining of the central canal. can have cystic components
3. Slow-growing, so associated with bony remodeling (scalloping of posterior vb, pedicle erosion, lamina thinning, all of which widens the spinal canal).
4. Associated with syrinx and non-tumoral cysts, perilesional edema.
5. Look for T2w hypointense hemosiderin cap at the bottom of lesion
6. Increased incidence in NF2, so ask to screen rest of neuroaxis.

Question 2

Imaging features of spinal ependymoma (intramedullary!)

Answer 2

1. Most common intramedullary spinal cord tumor in adults.
2. Well-defined, centrally located in the cord as arises from the ependymal lining of the central canal
3. Slow-growing, so associated with bony remodeling (scalloping of posterior vb, pedicle erosion, lamina thinning, all of which widens the spinal canal).
4. Associated with syrinx, perilesional edema.
5. Look for T2w hypointense hemosiderin cap
6. Increased incidence in NF2, so ask to screen rest of neuroaxis.

Question 3

Imaging feature of spinal hemangioblastoma (intramedullary!)

Answer 3

1. Seen superficially/pial surface. typically T1 isointense T2 hyperintense with cord edema. Signal
   is more heterogeneous with hemorrhage. Smaller lesions
   show solid enhancement, while larger lesions demonstrate
   the characteristic cystic mass with enhancing mural nodule.
2. Flow voids
3. Multiple lesions possible in VHL syndrome
4. Associated with syrinx formation

Question 4

Imaging features of myxopapillary ependymoma (considered intradural, extramedullary)

Answer 4

1. most common conus tumor
2. Occurs in the lumbosacral spine involving the filum terminale and/or conus medullaris.
3. Most prone to haemorrhage compared to other spinal ependymomas. LOOK FOR HEMOSIDERIN CAP. Otherwise similar to ependymomas are slow growing and can cause bony changes.
4. Smaller tumours tend to displace the nerve roots of the cauda equina; larger tumours often compress or encase them.
5. Differential diagnosis of a small conus and filum terminale myxopapillary ependymoma includes:
   - schwannoma
   - paraganglioma
6. Differential diagnosis of a large myxopapillary ependymoma that causes sacral destruction:
   - aneurysmal bone cyst: involving the spine
   - chordoma
   - giant cell tumour: involving the spine

Question 5

Imaging features of metastases (intramedullary!)

Answer 5

Intramedullary metastases are relatively uncommon. The most common primary neoplasms include lung carcinoma (especially small cell), breast carcinoma, melanoma, lymphoma, and renal cell carcinoma. There is typically a nidus of enhancement and extensive edema.

Pial metastatic
lesions can mimic hemangioblastomas.

Question 6

Imaging features of inflammatory/demyelinating spinal cord lesions (e.g. multiple sclerosis) (intramedullary!)

Answer 6

• preferentially involves the posterolateral cervical cord.
• flame-shaped lesions
  and T2 hyperintense with little or no cord swelling or edema.
• Enhancement may be seen during active demyelination. - Concomitant
  brain lesions are usually present.
• Lesions typically
  span less than two vertebral segments and involve less than half the cross-sectional area of the cord.
• Acute disseminated
  encephalomyelitis, however, may be more extensive.

Question 7

Differential diagnoses for intradural extramedullary spinal lesions “No more spinal masses PLSE!”

Answer 7

1. Neurofibroma
2. Meningioma
3. Schwanomma
4. Metastases
5. Paraganglioma
6. Lymphoma
7. Ependymoma, myxopapillary

Question 8

Imaging features of metastases (intradural extramedullary!)

Answer 8

“Drop” metastases, due to seeding from a primary CNS tumour, are more common in paediatric patients.

Metastases from a non-CNS primary tumour are more common in adults and
include primary cancers such as melanoma, lung and breast.

Question 9

What can be high T1 signal on spinal MRI?

Answer 9

subacute haemorrhage (methaemoglobin), fat, protein, melanin and contrast.

Metastatic Melanoma lesions will be T1-hyperintense AND enhance. Whereas dermoid and lipoma do not enhance.

Question 10

Imaging features of nerve sheath tumors: neurofibroma and schwannoma (intradural extramedullary!)

Answer 10

• Schwannoma is more common. They are circumscribed, iso- to hypointense to cord on T1, variably hyperintense on T2,
  and intensely enhance. Cystic change and hemorrhage may be
  seen with larger lesions. Most cases are solitary and sporadic; they may be multiple in the setting of NF-2.
• Neurofibromas
  (NFs) are often indistinguishable from schwannomas on
  imaging, especially when solitary and sporadic (90%). However, they are more likely to demonstrate the “target” sign with centrally decreased and peripherally increased T2 signal intensity.
  Multiple NFs are seen in patients with NF-1. Plexiform
  NFs are a specific subtype which demonstrate T2 hypointense septations and may undergo malignant degeneration in 5% of
  cases (suggested by rapid growth).

Other spinal stigmata of
NF-1 include thoracic scoliosis/kyphosis, vertebral anomalies, meningocele, and dural ectasia.

• Both tumours may have a
  “dumbbell” shape- occurs when the tumour has both an extradural and
  an intradural component and is narrowed in the middle as it passes through the neural foramen. Over time, the tumour will widen the neural foramen/posterior vb scalloping. This feature will allow you to distinguish a nerve sheath tumour from metastases and meningiomas.

Question 11

Imaging features of meningioma (intradural extramedullary)

Answer 11

• 2nd most common
  intradural extramedullary masses and are more common in
  women and patients with NF-2.
• vast majority (90%) are
  intradural; the remainder present as intra- and extradural, or rarely paraspinal or intraosseous.
• Usually in thoracic cord (75%)
  Lateral aspect of cord (90%)
  Broad-based dural attachment
  Dural tail
  Isointense to the cord on T1 and iso-hyper T2
  5% may calcify
  Early avid enhancement

Question 12

Imaging features of leukemia/lymphoma spine (intradural extramedullary!)

Answer 12

• Has a variety of imaging appearances within the spine, including leptomeningeal infiltration, intradural extramedullary spinal
  masses, epidural masses, and vertebral masses;
  
  • leptomeningeal involvement is the most common and presents with smooth or nodular enhancement.
• Intradural extramedullary masses typically occur in the setting of diffuse CSF involvement; a focal, solitary mass is rare. Intradural extramedullary lesions are often well circumscribed with homogeneous enhancement.