[Primary brain tumor complicating subdural hematoma].

A case of sphenoidal ridge meningioma complicating chronic subdural hematoma and a case of malignant astrocytoma producing not only intracerebral hematoma but also acute subdural hematoma were reported, and the mechanism of subdural hematoma formation was discussed according to the literature. Malignant glioma often produces intracranial hemorrhage, but scarcely produces subdural hematoma. On the other hand, meningioma scarcely produces intracranial hematomas, but among of them subdural hematoma is not unusual. The reason for it is probably due to the difference of the place where each tumor grows originally. Rupture of the bridging veins or the intratumoral abnormal vessels due to twisting of the brain from trivial head trauma or without trauma might produce subdural hematoma.