[Case of large sphenoid ridge meningioma treated by 2-stage surgery].

Large skull base meningiomas frequently encase the major cerebral vessels and cranial nerves, and receive blood supply from the branches of the internal carotid artery. One-stage resection of these tumors is difficult due to the long time needed for surgery and profuse bleeding from the tumor. We report herein a case of large sphenoid ridge atypical meningioma that was successfully resected using a combination of two-stage surgery and irradiation. A 56-year-old man was referred to us with mild left hemiparesis and visual deterioration. Computed tomography and magnetic resonance imaging showed a large sphenoid ridge meningioma. Angiography showed blood supply from the branches of both external and internal carotid arteries, and pial blood supply from the middle cerebral artery. In the first surgery after embolization of feeder vessels from the external carotid artery, the tumor was still hemorrhagic and was partially resected with 2,374 ml of blood loss. Symptoms were improved after the first surgery. Pathological diagnosis was atypical meningioma. In the second surgery after 40 Gy of irradiation, the remnant tumor was no longer hemorrhagic and was totally resected. Staged surgery with irradiation is one treatment option for large vascular skull base meningiomas, particularly for atypical meningiomas.