[Huge falx meningioma resected en bloc following acute brain swelling: a case report].

Surgery of a meningioma is composed of four essential consecutive steps; devascularization, detachment, debulking, and dissection. However, this is not the case with a huge meningioma in which circumferential devascularization and detachment may be difficult to complete before debulking is attempted. We report a case of a 37-year-old female presented headache, memory disturbance, and character change and sustaining a huge falx meningioma, with hypervascular appearance. Intraoperatively her blood pressure decreased to 45/30 mmHg due to profuse bleeding caused by "premature debulking" followed by significant brain swelling, which pushed out the tumor from the underlying brain after detachment of the tumor from the falx, and, consequently, yielded en bloc removal like a birth delivery. The histopathological diagnosis was angiomatous meningioma with prominent capillary proliferation without findings of celluar atypia. We thought that relative hyperemia in the brain surrounding the tumor, which was induced by the craniotomy, and acute brain ischemia caused by the intraoperative significant hypotension, might facilitate en bloc removal. We should be aware that huge meningiomas may cause intraoperative acute brain swelling as well as significant blood loss. Also we should carefully consider the indication and select proper candidates for presurgical cerebral angiography and tumor embolization because of the inherent risk that is apt to be underestimated.