title: Vascular hamartoma in the central nervous system of a foal.
abstract: Vascular hamartomas are non-neoplastic developmental anomalies of vessels. Cases of cerebral vascular hamartomas have been previously reported in dogs and cats. A 4-week-old Freiberger foal had shown persistent problems with breathing and swallowing since birth, and bilateral laryngeal paralysis was diagnosed. The foal subsequently developed left sided facial nerve paralysis and a secondary corneal ulcer in the left eye. Necropsy revealed a pinkish mass in the obex region of the brain. The mass was further investigated by histology and immunohistochemistry. Histologically, the mass consisted of many thin-walled, blood-filled vascular structures of variable diameter involving the white matter of the obex. The lining cells were immunohistochemically positive for factor VIII (von Willebrand factor) interpreted as endothelial cells. The endothelial lining showed also variable immunoreactivity for smooth muscle actin and vimentin. Normal neural parenchyma labeled with antibodies directed against glial fibrillary acidic protein and neuron-specific enolase was present between the vascular proliferations. A diagnosis of focal vascular hamartoma in the obex was made. The development of clinical signs is attributed to the compression of the surrounding neural parenchyma.
authors.affiliation: Institute of Veterinary Pathology (Borel, Grest), Vetsuisse Faculty, University of Zurich, Zurich, SwitzerlandClinic for Equine Internal Medicine, Equine Department (Junge, Wehrli Eser), Vetsuisse Faculty, University of Zurich, Zurich, Switzerland n.borel@access.uzh.ch.
authors.forename: Nicole
authors.initials: N
authors.lastname: Borel
authors.affiliation: Institute of Veterinary Pathology (Borel, Grest), Vetsuisse Faculty, University of Zurich, Zurich, SwitzerlandClinic for Equine Internal Medicine, Equine Department (Junge, Wehrli Eser), Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
authors.forename: Paula
authors.initials: P
authors.lastname: Grest
authors.affiliation: Institute of Veterinary Pathology (Borel, Grest), Vetsuisse Faculty, University of Zurich, Zurich, SwitzerlandClinic for Equine Internal Medicine, Equine Department (Junge, Wehrli Eser), Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
authors.forename: Hannah
authors.initials: H
authors.lastname: Junge
authors.affiliation: Institute of Veterinary Pathology (Borel, Grest), Vetsuisse Faculty, University of Zurich, Zurich, SwitzerlandClinic for Equine Internal Medicine, Equine Department (Junge, Wehrli Eser), Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
authors.forename: Meret
authors.initials: M
authors.lastname: Wehrli Eser
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001927:Brain Diseases / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D017809:Fatal Outcome; D020546:Fourth Ventricle / Q000473:pathology*; D006222:Hamartoma / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D006734:Horse Diseases / Q000175:diagnosis* / Q000473:pathology*; D006736:Horses; D007150:Immunohistochemistry / Q000662:veterinary
keywords: Foals; hamartoma; immunohistochemistry; nerve deficits; obex