title: Malignant epithelioid schwannoma of the oral cavity in a cat.
abstract: A malignant epithelioid schwannoma of the oral cavity was diagnosed in an 8-year-old domestic short-hair cat. The mass was located in the gingiva of the upper left premolar to molar region and showed multinodular growth patterns. The mass comprised epithelioid cells arranged in densely packed sheets. Tumor cells had large, round to oval nuclei with prominent nucleoli and an abundant eosinophilic cytoplasm. Immunohistochemically, most of the tumor cells were positive for S-100 protein, glial fibrillary acidic protein and vimentin, but all lacked melanoma-associated antigen and muscle and neuroendocrine markers. Stains for type IV collagen showed linear immunoreactivity around single cells and groups of cells. Ultrastructurally, tumor cells were separated by a well-defined basement membrane, and interdigitating cell processes were observed. To our knowledge, this is the first report of feline malignant epithelioid schwannoma.
authors.affiliation: Department of Veterinary Pathology, School of Veterinary Medicine, Kitasato University, 23-35-1, Higashi, Towada, Aomori 034-8628, Japan.
authors.forename: Hassadin
authors.initials: H
authors.lastname: Boonsriroj
authors.forename: Kazunori
authors.initials: K
authors.lastname: Kimitsuki
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Akagi
authors.forename: Chun-Ho
authors.initials: CH
authors.lastname: Park
mesh_terms: D000818:Animals; D002371:Cat Diseases / Q000473:pathology* / Q000601:surgery; D002415:Cats; D015622:Epithelioid Cells / Q000473:pathology; D005887:Gingival Neoplasms / Q000473:pathology / Q000601:surgery / Q000662:veterinary*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D007150:Immunohistochemistry / Q000662:veterinary; D009442:Neurilemmoma / Q000473:pathology / Q000662:veterinary*; D009418:S100 Proteins / Q000378:metabolism; D014746:Vimentin / Q000378:metabolism
chemical_list: D005904:Glial Fibrillary Acidic Protein; D009418:S100 Proteins; D014746:Vimentin