Intraosseous meningioma, also referred as primary intraosseous meningioma, is a rare subtype of meningioma that accounts for less than 1% of all osseous tumours. They fall under the sub group of primary extradural meningiomas.
It is important to note that this group of meningiomas does not include those intradural meningiomas which present with a intraosseous extension.
As with meningiomas in general there is recognised female predilection.
Clinical presentation is usually due to mass effect, the manifestations of which will depend on the location. The calvarium and verebral column are the most frequent sites 2.
- palpable or visible bony mass
- cranial nerve/spinal cord compression
- intracranial mass effect/hydrocephalus
Thought to occur from trapped arachnoid meningothelial cap cells within cranial sutures during development. However despite this theory only a small proportion of intraosseous meningiomas actually occur in association with a skull suture 3.
The majority ~65% are osteoblastic while ~35% are osteolytic 3. Due to this imaging appearances are non specific.
The commoner osteosclerotic type tends to show diffuse sclerosis with bony expansion.
- T1: may show an isointense extra axial mass component with the expanded bony component being low signal similar to the rest of the skull
- T2: meningioma component is typically isointense to grey matter while a small proportion can be hyper intense
- T1 C+ (Gd): as with conventional meningiomas typically tends to have unform avid contrast enhancement
Treatment and prognosis
They are generally benign and slow growing but there may be higher proportion of malignant change compared with standard meningiomas 3. Surgical resection with bone grafting may be performed in symptomatic cases.
For osteoblastic type consider:
- Paget disease: heterogeneous signal, non-enhancing
- craniofacial fibrous dysplasia: tends to be more extensive with more bony remodelling
- osteoma: non-enhancing
- osteosarcoma: irregular contours, heterogeneous signal and enhancement
- osteoblastic metastasis
For osteolytic type consider:
- imaging signs
- by location
- primary dural lymphoma
- Rosai-Dorfman disease
- solitary fibrous tumour of the dura
- EBV-associated smooth muscle tumour
- meningeal melanocytoma
- primary meningeal malignant melanoma
- Erdheim-Chester disease
- 1. Agrawal V, Ludwig N, Agrawal A et-al. Intraosseous intracranial meningioma. AJNR Am J Neuroradiol. 2007;28 (2): 314-5. AJNR Am J Neuroradiol (full text) - Pubmed citation
- 2. Moore SL, Chun JK, Mitre SA et-al. Intraosseous hemangioma of the zygoma: CT and MR findings. AJNR Am J Neuroradiol. 2001;22 (7): 1383-5. AJNR Am J Neuroradiol (full text) - Pubmed citation
- 3. Tokgoz N, Oner YA, Kaymaz M et-al. Primary intraosseous meningioma: CT and MRI appearance. AJNR Am J Neuroradiol. 2005;26 (8): 2053-6. AJNR Am J Neuroradiol (full text) - Pubmed citation
- 4. Geoffray A, Lee YY, Jing BS et-al. Extracranial meningiomas of the head and neck. AJNR Am J Neuroradiol. 5 (5): 599-604. AJNR Am J Neuroradiol (abstract) - Pubmed citation
Synonyms & Alternative Spellings
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