A primary intraosseous cystic meningioma: Case report.

Introduction: This is a very rare case of intraosseous cystic meningioma. There have been no reports of similar cases in the last 30 years.

Presentation Of Case: A 62-year-old man, suffering from a swelling of the lateral wall of the left orbit was admitted to our hospital. MRI and CT scan showed a large intradiploic lesion involving the lateral wall of the orbit and the greater wing of the sphenoid. The lesion was cystic with a mural nodule. We operated the patient and removed completely the mural nodule and the fibrous wall of cyst. Histological examination showed that the mural nodule was a benign meningothelial meningioma.

Discussion: Primary intraosseous meningiomas represent a subtype of primary extradural meningiomas; they comprise about 2% of all meningiomas and are therefore rare entities. Cystic meningiomas are rare, their incidence compared to all other types of meningiomas is of 2-4%. The presence of a meningioma with both characteristics: cystic and intraosseous, like in our case, is an exceptional occurrence.

Conclusion: The surgical management of tumor was easy; its rarity means that the case is interesting.