Sphenoid wing meningioma en plaque: report of 37 cases.

Background: Sphenoid wing meningioma en plaque is a special morphological subgroup of intracranial meningiomas, defined by a carpet-like, soft tissue component that infiltrates the dura and invades the sphenoid wing and orbit associated with a significant hyperostosis. This report summarized our experiences in 37 patients with sphenoid wing meningioma en plaque who had been treated with transcranio-orbital approach surgery.

Methods: A retrospective study was made on clinical manifestations, neuroradiological features, and operative techniques in 37 patients undergoing transcranio-orbital approach from Sep. 1998 to Apr. 2009. Patients ages: 16 years to 67 years, 45.5 years in average; sex: 15 males, 22 females. Chief complaints were progressive proptosis and visual acuity deficits. All patients were operated on using a fronto-temporal approach with orbital decompression. The extent of tumor resection and postoperative complications were investigated.

Results: Simpson grade II resection was achieved in 9 patients, Simpson grade III in 22 patients and Simpson grade IV in 6 patients. Pathological examination showed 27 (73%) patients were meningothelial meningiomas. After surgery, proptosis improved in all patients, visual acuity improved in 18 patients (69%). Temporary ophthalmoplegia was found in 8 patients, cerebrospinal fluid leak was found in 1 patient. Duration of follow up was from 3 months to 9 years, tumor recurred in 7 patients, and 5 patients underwent second surgery, including two trans-nasal endoscopic surgeries to resect sphenoid sinus-involved tumor. There were no operation-related deaths or other significant complications.

Conclusions: Sphenoid wing meningioma en plaque, mainly meningothelial meningiomas, are more likely to produce adjacent hyperostosis and have characteristic radiological appearances. All the hyperostosis bone of the great wing of sphenoid bone should be removed to prevent recurrence. Extensive tumor removal with bony decompression at the orbital apex can produce satisfactory cosmetic and functional outcome. Close co-operation between the neurosurgeons and the ophthalmologists is important.