title: Falx meningioma presenting as acute subdural hematoma: case report.
abstract: BACKGROUND
  Acute subdural hematomas caused by meningiomas have been rarely encountered. Pathophysiologic mechanisms and clinical considerations in these patients have not been sufficiently explored. We addressed the possible mechanism of spontaneous hemorrhage in our case and briefly discuss the optimal treatment.
  
  
  METHODS
  This case of falx meningioma presenting as an acute subdural hematoma in a 78-year-old woman is described. On initial computed tomography (CT), an enhancing tumor of the falx appeared to be the cause of hemorrhage. Only faint contrast staining in the periphery of the tumor was seen on right external carotid arteriograms, with no evidence of other vascular supply. Extravasation of contrast material during the procedure occurred suddenly and was successfully treated by endovascular embolization using a microcatheter. The hematoma was emergently evacuated with gross total removal of the tumor. Pathologic examination confirmed a transitional meningioma with abundant hyalinized structures. Disruption of a thin-walled vessel adjacent to the tumor capsule was assumed to be the site of hemorrhage.
  
  
  CONCLUSIONS
  The longstanding ischemia of the tumor was considered to have produced the deposition of hyalin in the tissue, which changed the hemodynamics within the tumor, producing vascular stress leading to rupture. The prognosis of patients with meningiomas complicated by acute subdural hematoma is generally poor, with mortality reported in approximately one-half of such patients. Surgical exploration is the most effective treatment and should be conducted before irreversible brain damage has occurred.
authors.affiliation: Department of Neurosurgery, Osaka Neurological Institute, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Okuno
authors.forename: H
authors.initials: H
authors.lastname: Touho
authors.forename: H
authors.initials: H
authors.lastname: Ohnishi
authors.forename: J
authors.initials: J
authors.lastname: Karasawa
mesh_terms: D000208:Acute Disease; D000368:Aged; D001932:Brain Neoplasms / Q000175:diagnosis; D005260:Female; D006408:Hematoma, Subdural / Q000209:etiology*; D006801:Humans; D008577:Meningeal Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D008579:Meningioma / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D014057:Tomography, X-Ray Computed