The vast majority (90%) of spinal meningiomas are extramedullary intradural in location. Occasionally (5%) purely extradural tumours are found and the remainder (5%) have both intradural and extradural components taking on a dumbbell appearance.
Interestingly spinal meningiomas are also not distributed evenly along the spinal canal:
Cervical spinal meningioma - 15%
thoracic spine - 80%
lumbosacral spine: uncommon
Meningiomas are often located posterolaterally in the thoracic region and anteriorly in the cervical region.
Most meningiomas are solitary lesions (98%). Multiple meningiomas are most often associated with NF2.
usually normal
rarely bone erosion or calcification.
Isodense or moderately hyperdense mass
hyperostosis may be seen but is not as common as in the intracranial forms
calcification may be present