A 63-year-old woman presented with a ruptured aneurysm which apparently spontaneously thrombosed. She was admitted after sudden onset of severe headache. Computed tomography (CT) demonstrated subarachnoid hemorrhage (SAH) in the pontine and interpeduncular cisterns. Initial threedimensional CT (3D-CT) angiography revealed an aneurysm (diameter, 9 mm) near the origin of the left superior cerebellar artery. However, angiography 3 hours later failed to show the aneurysm. Total thrombosis was thought to have occurred in the aneurysm. The patient returned home with no deficit 1 month after admission. T 1 -and T 2 -weighted magnetic resonance imaging 75 days after the SAH demonstrated the thrombosed aneurysm as an isointense mass lesion. 3D-CT angiography showed no recanalization of the aneurysm 9 months after the SAH.

A 66-year-old man presented with clival chordoma associated with subarachnoid hemorrhage. Computed tomography showed subarachnoid hemorrhage in the right ambient cistern and a well-enhanced tumor in the petroclival region. Surgical exploration performed on the day of admission showed a clot in the tumor. The tumor was totally removed. Histological examination showed hemorrhage between the tumor and the dura. The diagnosis was clival chordoma. Subarachnoid hemorrhage in chordoma seems to occur by spreading of intratumoral hemorrhage into the subarachnoid space due to dural invasion.

A 59-year-old woman with type IIA von Willebrand's disease (VWD) presented with subarachnoid hemorrhage (SAH). Computed tomography showed SAH in the right sylvian fissure and intracranial hemorrhage in the right temporal lobe. Angiography demonstrated an aneurysm at the bifurcation of the right middle cerebral artery. Neck clipping was performed on the 3rd day after the onset with intraand postoperative administration of factor VIII/von Willebrand factor concentrate. No excessive bleeding occurred. Patients with prolonged bleeding time should be screened for VWD before surgery. This is a rare case of VWD presenting with SAH secondary to ruptured intracranial aneurysm. The clinical characteristics and the management of SAH in a patient with VWD are discussed.