Meningiomas arising from the coverings of the spinal cord represent a minority of all meningiomas (approximately 12% 5) but are the second most common intradural extramedullary spinal tumour representing 25% of all such tumours 2. Despite usually being small, due to the confines of the spinal canal they can result in significant neurologic dysfunction.
This article specifically relates to spinal meningiomas. For a discussion on intracranial meningiomas and a general discussion of the pathology refer to the main article: meningioma.
Spinal meningiomas have a peak incidence in the fifth and sixth decades. Interestingly, and unlike intracranial meningiomas, in the adult population, females are approximately ten times more commonly affected than males. In children, there does not appear to be a sex predilection.
There is an increased incidence of spinal meningiomas in patients with neurofibromatosis type 2, and in fact in the paediatric population, meningiomas uncommonly occur outside of the setting of NF2.
The majority of patients present with motor deficits as a result of compression of the spinal cord. Less common presentations include sensory deficits, pain and sphincter dysfunction.
Most spinal meningiomas are benign, with greater than 95% being classified as WHO grade I lesions, although clear cell meningiomas (a WHO grade II histological variant) have a predilection for the spine 6,7. They are believed to originate from the denticulate ligaments.
For a discussion of the pathology of meningiomas, refer to the general meningioma article.
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 appearance2.
Interestingly spinal meningiomas are also not distributed evenly along the canal:
- cervical spine - 15%
- thoracic spine - 80%
- lumbosacral spine: uncommon 2
Meningiomas are often located posterolaterally in the thoracic region and anteriorly in the cervical region 6.
Most meningiomas are solitary lesions (98%). Multiple meningiomas are most often associated with NF2 6.
- 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
- broad-based dural attachment
- dural tail sign
They share similar signal characteristics to typical intracranial meningiomas:
- isointense to slightly hypointense
- may have a heterogeneous texture
- T2: isointense to slightly hyperintense
- T1 C+ (Gd): moderate homogeneous enhancement
Occasionally, densely calcified meningiomas are hypointense on T1 and T2, and show only minimal contrast enhancement.
Treatment and prognosis
Spinal meningiomas are typically slow growing. Surgery is the treatment of choice and complete tumour removal is achieved in the vast majority of patients. Less than 10% experience recurrence 2.
- typically located anteriorly (compared to meningiomas that are usually located posterolaterally)
- tendency for multiplicity
- may have low-intensity central regions on post-contrast T1 and T2 weighted images
- not associated with a broad dural base
- neural exit foraminal widening is more commonly seen with nerve sheath tumours
- 1. Brant WE, Helms CA. Fundamentals of Diagnostic Radiology. Lippincott Williams & Wilkins. (2006) ISBN:0781765188. Read it at Google Books - Find it at Amazon
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- 4. Soderlund KA, Smith AB, Rushing EJ et-al. Radiologic-pathologic correlation of pediatric and adolescent spinal neoplasms: Part 2, Intradural extramedullary spinal neoplasms. AJR Am J Roentgenol. 2012;198 (1): 44-51. doi:10.2214/AJR.11.7121 - Pubmed citation
- 5. Buetow MP, Buetow PC, Smirniotopoulos JG. Typical, atypical, and misleading features in meningioma. Radiographics. 1991;11 (6): 1087-106. Radiographics (citation) - Pubmed citation
- 6. Abul-kasim K, Thurnher MM, Mckeever P et-al. Intradural spinal tumors: current classification and MRI features. Neuroradiology. 2008;50 (4): 301-14. doi:10.1007/s00234-007-0345-7 - Pubmed citation
- 7. Lee W, Chang KH, Choe G et-al. MR imaging features of clear-cell meningioma with diffuse leptomeningeal seeding. AJNR Am J Neuroradiol. 2000;21 (1): 130-2. AJNR Am J Neuroradiol (full text) - Pubmed citation
- grading and histological variants
- grade I
- meningothelial meningioma
- fibrous meningioma
- microcystic meningioma
- psammomatous meningioma
- angiomatous meningioma
- secretory meningioma
- metaplastic meningioma
- lymphoplasmacyte-rich meningioma
- grade II
- grade III
- grade I
- imaging signs
- by location
- Simpson grade (of resection)
- grading and histological variants
- solitary fibrous tumour of the dura
- primary dural lymphoma
- Rosai-Dorfman disease
- EBV-associated smooth muscle tumour
- meningeal melanocytoma
- primary meningeal malignant melanoma
- Erdheim-Chester disease
- dural metastases
- hypertrophic pachymeningitis