Epidemiology
Spinal meningiomas can occur at any age, but are most common between the 5th and 7th decades of life. It is also more common in women (75-85% of all spinal meningiomas) and in the thoracic spine (90% of all meningiomas).
Pathology
Meningiomas of the spine are thought to arise from the arachnoid cap cells of arachnoid villi (aka arachnoid granulations). Arachnoid villi in the spine are concentrated mainly over the nerve roots, and the meningiomas tend to rise more laterally. However, the origin of meningiomas is still controversial. It is thought that the ventral and dorsal spinal meningiomas might arise from fibroblast cells of the arachnoid or the pia mater.
Most spinal meningiomas belong to the psammomatous histological type.
Spinal and convexity meningiomas of ten have 22q deletions and/or NF2 mutations
Spinal meningiomas are associated with the following syndromes:
- NF2
- Familial clear cell meningioma syndrome
- Multiple meningiomatosis
Clinical features
The symptoms include:
- mild pain
- insidious neurological deficit
Increasingly, many of the spinal meningiomas are incidentally found
Differential diagnosis
The differential diagnosis of intradural extramedullary spinal meningiomas is:
- schwannoma
- ependymomas, myxopapillary
- lymphomas
- metastases
However, meningiomas can be intradural with extradural extension, extradural, intramedullary, intraosseous or paraspinous.
Investigations
CT scan:
- Calcification 1-5%
- Rare for bone remodelling ( might occur in the foramina)
- Strong contrast enhancement
MRI scan:
- ventral or ventrolateral
- non-contrast enhanced scans: isodense with the cord (T1 and T2)
- uniformly contrast-enhancing
- if calcified, it might not enhance
- dural tail (58%)
| Meningioma | Schwannoma | Ependymomas | Mets | neurofibroma | lymphoma | chordoma | Haemangioma | paraganglioma | epidermoid | Arachnoid cysts | |
| epidemiology | Multiple, history | Rare900 | rare | ||||||||
| lumbar | |||||||||||
| Dura based | + | If large abuts dura | If large abuts dura | ||||||||
| T1 | Iso | solitary | low | Identical to CSF | |||||||
| T2 | Iso | increased | Identical to CSF | ||||||||
| Contrast | avid | variable | avid | No central enhancement | |||||||
| Diffusion weights | |||||||||||
| cysts | |||||||||||
| Calcification | |||||||||||
| Haemorrhage | yes | ||||||||||
| Haemosiderin cap | Yes |
| Feature | Meningioma | Schwannoma | Neurofibroma |
| Typical Location | Thoracic spine, intradural extramedullary | Lumbar spine, intradural/extradural | Cervical spine, intradural/extradural |
| Shape | Oval, sometimes with “ginkgo leaf” sign | Lobulated or dumbbell-shaped | Spindle-shaped, sometimes “target sign” |
| T2 MRI Signal | Iso- to hyperintense; less fluid signal | Hyperintense, often with cystic changes | Hyperintense, often with “target sign” |
| Enhancement Pattern | Diffuse, homogeneous; frequent dural tail | Rim or heterogeneous enhancement | Variable, less rim enhancement |
| Calcification (CT) | Common (up to 58%) | Rare | Rare |
| Dural Tail Sign | Common (up to 75%) | Rare | Rare |
| Neural Foraminal Ext. | Rare | Common (dumbbell shape) | Common |
| Cystic Change | Uncommon | Common (up to 96%) | Less common than schwannoma |
(Table generated from Consensus AI)
Surgical Management
The following website includes operative videos which give an excellent outline of the surgical excision of spinal meningiomas:
Meningiomas | JNS Focus Videos | WAM Fisher…M Galgano | [web]
meningioma | JNS Focus video | Tigre J…Burks SS | [web]
