title: Equine papillary ependymoma.
abstract: A 17-year-old Arabian gelding with progressive neurologic signs had a velvety, reddish brain tumor protruding from the ventral midline caudal to the optic chiasma. Histologically, the tumor had a papillary formation with a single layer of elongate cells radially oriented around a central fibrovascular core. Intracytoplasmic globular inclusions were positive for glial fibrillary acidic protein and weakly positive for vimentin. Ultrastructurally, these inclusions were comprised of whorling intermediate filaments. Neoplastic cells also had cytoplasmic interdigitations and numerous zona adherens and often rested on a basal lamina. The tumor was diagnosed as a papillary ependymoma.
authors.forename: M J
authors.initials: MJ
authors.lastname: Carrigan
authors.forename: R J
authors.initials: RJ
authors.lastname: Higgins
authors.forename: G P
authors.initials: GP
authors.lastname: Carlson
authors.forename: D K
authors.initials: DK
authors.lastname: Naydan
mesh_terms: D000818:Animals; D001923:Brain Chemistry; D001932:Brain Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D004806:Ependymoma / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis / Q000378:metabolism; D006734:Horse Diseases / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D006736:Horses; D007150:Immunohistochemistry; D007382:Intermediate Filaments / Q000648:ultrastructure; D008297:Male; D014746:Vimentin / Q000032:analysis / Q000378:metabolism
chemical_list: D005904:Glial Fibrillary Acidic Protein; D014746:Vimentin