title: Intraarterial schwannoma in horizontal segment of middle cerebral artery causing subarachnoid hemorrhage.
abstract: A spontaneous subarachnoid hemorrhage (SAH) from the middle cerebral artery is most commonly caused by the rupture of saccular aneurysms and rarely by fusiform aneurysms or arterial dissections/dissecting aneurysms. To the authors' knowledge, this is the first report of an intraarterial neoplasm causing an SAH. A 44-year-old woman presented with an SAH in the basal cisterns. Subsequent internal carotid artery angiography demonstrated a small bulge on the superior wall of the horizontal (M1) segment of the middle cerebral artery. However, a pterional craniotomy revealed a well-circumscribed solitary tumor with a diameter of 15 mm involving the superior wall of the M1 segment as the cause of the SAH. Pathological examination demonstrated typical findings of a schwannoma, elongated cells with tapered, spindle-shaped nuclei and indistinct cell borders, and diffuse immunoreactivity for the S100 protein.
authors.affiliation: Department of Neurosurgery, Cardiocerebrovascular Center, Kyungpook National University, Daegu, Republic of Korea. jparkmd@hotmail.com
authors.forename: Jaechan
authors.initials: J
authors.lastname: Park
authors.forename: Dakeun
authors.initials: D
authors.lastname: Lee
mesh_terms: D000328:Adult; D000792:Angiography; D003399:Craniotomy; D005260:Female; D006801:Humans; D020768:Middle Cerebral Artery / Q000378:metabolism / Q000473:pathology; D009442:Neurilemmoma / Q000150:complications* / Q000473:pathology / Q000601:surgery; D009418:S100 Proteins / Q000378:metabolism; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging / Q000209:etiology*; D016896:Treatment Outcome; D019043:Vascular Neoplasms / Q000150:complications* / Q000473:pathology / Q000601:surgery
chemical_list: D009418:S100 Proteins