Spheno-orbital Meningiomas—Surgical Technique and Outcome

Introduction: Intraosseus meningiomas of the base of the anterior and middle cranial fossa involving the sphenoid wing and orbit are a rare form of meningioma growth. The literature refers to terms as meningioma en plaque, intraosseus meningioma, or spheno-orbital meningioma (SOM). The present study describes a surgical series of 65 such tumors.

Material and Methods: Charts of patients operated for SOM by or under supervision of the senior author at the Neurosurgical Departments of the University of Erlangen and Bonn were retrospectively reviewed for presenting symptoms, surgical technique, and clinical outcome.

Results: During 1983 to 1989 (Erlangen) and 1989 to 2003 (Bonn), 65 patients (mean age: 51±11 years; range: 21–77; 52 female, 13 male) were surgically treated in 76 procedures. The most common symptom was proptosis (n = 44), followed by visual deficits (n = 17), pterional soft tissue swelling (n = 17), and others. Twenty-one patients had visual field deficits, 26 patients a visual acuity < 0.6. Other cranial nerve palsies were present in 17 patients (6 cranial nerve III, 5 cranial nerve IV, 2 cranial nerve V, 2 cranial nerve VI, 2 cranial nerve VII, 6 double vision). Three patients presented with bilateral tumors. In 65 cases the lesser sphenoid wing was largely resected; the lateral orbital wall was resected in 56 cases; the orbital roof in 63; and optic canal decompression was performed in 45 cases. Periorbital tumor infiltration led to intraorbital resection in 34 cases; 4 cases presented a solid intraorbital tumor. The middle fossa base was resected in 46 cases. Fifty-seven cases were associated with a dural involvement, and 14 pterional bone flaps were tumor infiltrated. Median follow-up was 4.5 years (range: 0–17 years). Twenty-six patients showed stable tumor residuals; 14 progressive tumor rests. One patient presented with a contralateral tumor recurrence. Eleven were operated for recurrent meningiomas, with 4 treated by radiation therapy. Twelve patients showed temporary oculomotor deficits, while 8 had permanent deficits. Temporary ptosis was observed in 9 cases and persisted in 2. Two patients showed new cranial nerve V deficits.

Conclusions: SOM are rare tumors. Since involvement of delicate structures of the orbital cone is common, complete surgical resection is frequently impossible. Some persisting neurological deficits are possible, whereas proptosis and other visual deficits are usually relieved. Two thirds of tumor rests remained stable during follow-up. Consequently, the aim should be the relief of leading symptoms and not radical resection.