Incidental Meningioma　天幕下急性硬膜下血腫術中に発見された1例

抄録

The authors report the incidental discovery of a meningioma during surgery for an acute infratentorial subdural hematoma. The patient was a 46-year-old female admitted for severe head trauma. A plain skull X-ray showed a sharp linear fracture in the left posterior region, extending from the parietal area to the foramen magnum. An initial computed tomographic scan demonstrated a highdensity intracranial mass in the left posterior fossa. Three hours after onset, the patient underwent emergency craniectomy and a subdural hematoma weighing 30 g was aspirated. During this procedure, an infratentorial tumor 30 mm in diameter was found to be attached to the dura and was totally removed. The tumor was a fibroblastic meningioma. The patient's postoperative course was uneventful. Most incidentally discovered meningiomas have been found in patients with ruptured aneurysms or chronic subdural hematomas. This is the first reported case in which the tumor was found in association with an acute infratentorial subdural hematoma.