title: Hemangiopericytoma: collision with meningioma and recurrence.
abstract: Intracranial hemangiopericytomas are a rare type of primary brain tumor, representing only about 0.5% of all primary brain tumors. Even more rare is the co-existence of two juxtaposed primary brain tumors, termed a "collision" tumor. This report provides the first documentation in the literature of a hemangiopericytoma colliding with a meningioma, and recurring after treatment with gross total resection. Surgical samples were fully evaluated with hematoxylin and eosin and reticulin staining, as well as immunohistochemical analysis. Results were classically representative of a hemangiopericytoma (World Health Organization grade II) and of a meningioma (World Health Organization grade I). This report of a unique collision tumor not only augments the repertoire of collision tumor combinations described in literature but also provides follow-up on the clinical outcome of the patient, thereby raising clinically relevant issues ranging from presentation to treatment paradigms.
authors.affiliation: Department of Neurosurgery, Mount Sinai School of Medicine, 1 Gustave L. Levy Place, Box 1136, New York, NY 10029, USA. emanuela.binello@mssm.edu
authors.forename: Emanuela
authors.initials: E
authors.lastname: Binello
authors.forename: Joshua B
authors.initials: JB
authors.lastname: Bederson
authors.forename: George M
authors.initials: GM
authors.lastname: Kleinman
mesh_terms: D000328:Adult; D018952:Antigens, CD34 / Q000378:metabolism; D001932:Brain Neoplasms / Q000150:complications* / Q000175:diagnosis / Q000378:metabolism; D006393:Hemangiopericytoma / Q000150:complications* / Q000175:diagnosis / Q000378:metabolism; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008577:Meningeal Neoplasms / Q000150:complications* / Q000175:diagnosis / Q000378:metabolism; D008579:Meningioma / Q000150:complications* / Q000175:diagnosis / Q000378:metabolism; D009364:Neoplasm Recurrence, Local / Q000150:complications* / Q000378:metabolism; D012008:Recurrence
chemical_list: D018952:Antigens, CD34