Primär extradurales Meningeom der Orbita: Ein Bericht über einen Patienten sowie Literaturübersicht

Background Over 98% of all meningiomas originate in the central nervous system including the optic fascicle. Spread outside this area occurs in 20% of cases. Ectopic (extradural) meningiomas that do not originate from either the optic fascicle or the intracranial meninges are exceedingly rare. We treated a patient with an ectopic meningioma of the orbit and reviewed the literature concerning ectopic orbital meningiomas. History and signs A 30-year-old man presented with a painless tumor in the left medial canthal area. This tumor had developed over a period of two years. The patient complained of intermittent epiphora. Ophthalmologic examination revealed a slight lateral displacement of the left eye. There was a palpable medial orbital mass with an otherwise normal ophthalmological examination. Computed tomography and magnetic resonance imaging showed a homogeneous, well-marginated soft tissue mass. Therapy and outcome The lesion which had neither a contact to the dura of the anterior cranial fossa nor to the optic fascicle was excised and histologic examination showed a fibroblastic meningioma. There was no recurrent tumor after a follow-up of 18 months. Conclusion Less than 50 ectopic (extradural) meningiomas of the orbit have been described in the literature. The most common histologic type is the meningotheliomatous (syncytial or transitional) meningioma. The mean age at diagnosis of these tumors is 31 years. After complete resection the prognosis is good.