PRIMARY EXTRADURAL INTRAORBITAL MENINGIOM A - A CASE PRESENTATION ANDREVIEW OF THE LITERATURE

Background Over 98% of all meningiomas originate in the central nervou s system including the optic fascicle. Spread outside this area occurs in 20% of cases, Ectopic (extradural meningiomas that iio not origina te from either the optic fascicle or the intracranial meninges are exc eedingly rare. We treated a patient with an ectopic meningioma of the orbit and reviewed the literature concerning ectopic orbital meningiom as. History and signs A 30-year-old man presented with a painless tumo r in the left medial canthal area. This tumor had developed over a per iod of two years. The patient complained of intermittent epiphora. Oph thalmologic examination revealed a slight lateral displacement of the left eye. There was a palpable medial orbital mass with an otherwise n ormal ophthalmological examination. Computed tomography and magnetic r esonance imaging showed a homogeneous, well-marginated soft tissue mas s. Therapy and outcome The lesion which had neither a contact to the d ura of the anterior cranial fossa nor to the optic fascicle was excise d and histologic examination showed a fibroblastic meningioma. There w as no recurrent tumor after a follow-up of 18 months. Conclusion Less than 50 ectopic (extradural) meningiomas of the orbit have been descri bed in the literature. The most common histologic type is the meningot heliomatous (syncytial or transitional) meningioma. The mean age at di agnosis of these tumors is 31 years. After complete resection the prog nosis is good.