Meningiomas are the most common benign tumors of the brain (95% of benign tumors). However they can also be malignant. They arise from the arachnoidal cap cells of the meninges and represent about 15% of all primary brain tumors. They are more common in females than in males (2:1) and has a peak incidence in the sixth and seventh decades. Most cases are sporadic while some are familial. There has been some evidence that persons who have undergone radiation to the scalp are more at risk for developing meningiomas. The most frequent genetic mutations involved in meningiomas are inactivation mutations in the neurofibromatosis 2 gene (merlin) on chromosome 22q.
Treatment:
Surgical resection -- Meningiomas can usually be surgically resected with permanent cure if the tumor is superficial on the dural surface and easily accessible. Transarterial embolization has become a standard preoperative procedure in the preoperative management.[1] For incompletely accessible tumors, recurrence is likely. These regions include the medial sphenoid bone, parasellar region, or anterior brainstem. If invasion of the adjacent bone occurs, total removal is nearly impossible. Malignant transformation is rare.
Radiation therapy include Gamma KnifeTM or proton beam treatment may be pursued in cases of inoperable or unresectable tumors, or if tumor shows malignant transformation. Focused radiation may also be helpful for small tumors at the base of the skull.
Conventional chemotherapy is likely not effective. Antiprogestin agents have been used but with variable results. Recent evidence that hydroxyurea has the capacity to shrink unresectable or recurrent meningiomas is being further evaluated.