The management of meningiomas of the sphenoid wing

This is a retrospective study of the clinical characteristics, neuroradiologic features, histology, and outcome of treatment among 95 patients with meningiomas of the sphenoidal ridge. The patients were treated in the Departments of Neurosurgery, Ludwig-Maximillians University Munich (56 patients), and the University of Bern in Switzerland (39 patients). The Munich series consisted of admissions between 1988 and 1994. Some of these were readmissions for recurrent disease therefore longer follow up data from as far back as 1978 were available for them. All the Munich patients were followed up for at least 5 years. The average follow up for the Bern patients was 28.1 months. Recurrence-free survivals, overall recurrence rates and the benefits of radiation for subtotally excised tumours are evaluated. The ages of the patients ranged from 30 to 81 years with a mean of 59 years. The peak tumour frequency was in the age range 46.4 years to 68.6 years. The male-female ratio was 1:2.4. There was a preponderance of medial over lateral tumours (63% medial, 34% lateral) and 3% were en plaque lesions extending from the pterion for varying extents toward the midline. Two patients had multiple meningiomas. The symptoms could be clearly separated into those due to medial tumours and those due to lateral tumours with visual complaints occurring in medial tumours and one sided symptoms in lateral tumours. The neuroimaging modality was CT scan and selective angiography in all cases and in addition MRI in 50 (53%) patients. CT imaging gave a diagnostic yield of 96% but the MRI had a superior resolution and was able to demonstrate vascular involvement. The blood supply was from branches of the ethmoidal artery in 41%, from branches of the middle meningeal artery in 26% and from intracavernous branches of the internal carotid artery in 25% of cases. Surgery was performed in 91 patients. In 42 (46%) patients the excision was complete (Simpson grade 1). When Simpson grades l and 2 were considered together (68 cases) they constituted 75% of all excisions. Macroscopic residual tumour (Simpson 3 and 4) was present in 25% of cases. In the Munich series failure of complete removal was due to cavernous sinus invasion in 7 (12.5%) cases and extensive bone involvement in 4 (7.7%). The overall surgical mortality was 3.4%. Tumour recurrence/progression was 5.5% for totally excised tumours and 23% for sub totally excised tumours at 5 years. Radiotherapy was offered in 11 patients in the Munich series but not in the Bern series. There was a trend towards a beneficial outcome after radiation in the control of sub totally excised tumours where the progression-free survival of 75% at 5 years in this group was better than the expected survival of 45% to 59%. Owing to the small number of irradiated patients the outcome of radiation treatment could not be subjected to a statistical evaluation. It is concluded that from the trend observed radiation therapy has a place in the treatment of sub totally removed meningiomas. Prospective studies are recommended