title: Surgical removal of a choroid plexus oncocytoma in an adult cat.
abstract: An 11-year-old male castrated domestic shorthair cat presented with left central vestibular dysfunction. Magnetic resonance imaging of the brain revealed a large, extra-parenchymal, strongly contrast-enhancing mass at the level of the left cerebellopontine angle and compressing the cerebellum and brainstem. The mass was surgically excised via left rostral and sub-tentorial craniectomies and histopathology revealed an epithelial neoplasm composed of anastomosing cords of neoplastic cells that contained large amounts of finely granular hypereosinophilic cytoplasm and round nuclei. The cytoplasmic granules were variably positive with periodic acid-Schiff and modified Gomori trichrome. Immunohistochemical staining with anti-cytokeratin AE1/AE3 was diffusely positive. Electron microscopy revealed neoplastic cells that were full of electron-dense organelles consistent with mitochondria. This is the first case of a choroid plexus oncocytoma in the central nervous system of any domestic animal species and highlights the role of successful surgical intervention in extra-parenchymal neoplasia in the central nervous system.
authors.affiliation: Section of Anatomic Pathology, Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA.
authors.forename: B
authors.initials: B
authors.lastname: Cossic
authors.affiliation: Massachusetts Veterinary Referral Hospital, Woburn, Massachusetts 01801, USA.
authors.forename: G
authors.initials: G
authors.lastname: Silver
authors.affiliation: Section of Small Animal Medicine and Surgery, University of Georgia College of Veterinary Medicine, Athens, Georgia 30602, USA.
authors.forename: M
authors.initials: M
authors.lastname: Kent
authors.affiliation: Red Bank Veterinary Hospital, Tinton Falls, New Jersey 07724, USA.
authors.forename: E N
authors.initials: EN
authors.lastname: Glass
authors.affiliation: Diagnostic Center for Population and Animal Health, Michigan State University, Lansing, Michigan 48824, USA.
authors.forename: D
authors.initials: D
authors.lastname: Agnew
authors.affiliation: Section of Anatomic Pathology, Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA.
authors.forename: S
authors.initials: S
authors.lastname: McDonough
authors.affiliation: Section of Anatomic Pathology, Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA.
authors.forename: A D
authors.initials: AD
authors.lastname: Miller
mesh_terms: D018249:Adenoma, Oxyphilic / Q000175:diagnosis / Q000601:surgery / Q000662:veterinary*; D000818:Animals; D002371:Cat Diseases / Q000175:diagnosis / Q000601:surgery*; D002415:Cats; D002831:Choroid Plexus; D008279:Magnetic Resonance Imaging / Q000662:veterinary*; D008297:Male; D008854:Microscopy, Electron; D013116:Spinal Cord