Object. The authors analyzed the long-term results and radiological aspects of sphenoorbital meningioma (with emphasis on exophthalmos) in a series of 30 patients who underwent resection. Methods. Data obtained in all 30 patients who underwent surgery for typical sphenoorbital meningioma at the authors' institution between June 1994 and September 2005 were analyzed retrospectively. The exophthalmos index (EI) was measured on preoperative MR images and/or CT scans and compared between the early and last follow-up examinations. All patients were women 35-74 years of age (median 51 years). Exophthalmos was the presenting symptom in 28 patients (93%), and was observed on preoperative MR images in all patients. The median duration of symptoms before surgery was 10 months (2-120 months). Results. Total resection (Simpson Grade I) was not achieved in these patients because of the impossibility of resecting the dura mater in the superior orbital fissure without causing significant complications. Subtotal resection (Simpson Grade II) was obtained in 90% of patients, and in 3 patients (10%) a portion of the tumor was deliberately left in place because of extensive macroscopic infiltration of the cavernous sinus and/or extraocular muscles (Simpson Grade III). No patient died. Radiological evaluation at a median follow-up of 61 months (range 17-136 months) showed no contrast enhancement in 14 patients (47%), residual contrast enhancement without evolution in 13 (43%), and recurrence (new contrast enhancement) in 3 (10%). The EI was improved at the first radiological follow-up (median 12 months) in 27 patients (90%), and at the last radiological follow-up (median 61 months) in 28 patients (93%). In the interval between the first and final imaging follow-up, the EI improved in only 8 patients (20%), worsened in 15 patients (50%), and showed no variation in 7 patients (30%). Conclusions. Sphenoorbital meningiomas are insidious tumors with slow progression. Even when exophthalmos is not clinically evident, it is always present on preoperative MR imaging. Total resection is not possible due to superior orbital fissure invasion, but subtotal resection (Simpson Grade II) can assure long-term stability due to the nonevolutive nature of most residual tumors. Exophthalmos improves at early radiological follow-up, but may worsen again as time passes. (DOI: 10.3171/2009.1.JNS081263)
