Duarte, et al.; Nasal polyposis in a cow. Braz J Vet Pathol, 2015, 8(3), 102 - 106 Brazilian Journal of Veterinary Pathology. www.bjvp.org.br . All rights reserved 2007. 102 Case Report Nasal polyposis in a cow Roberta P. Duarte * , Paulo Ricardo D. Rocha, Augusto Schweigert, Fernando C. G. Morelli, Gisele F. Machado Faculdade de Medicina Veterinária, Universidade Estadual Paulista Júlio de Mesquita Filho - UNESP, Araçatuba, SP, Brazil. * Corresponding author: E-mail: robertapicciuto.medvet@hotmail.com Submitted August 13 th 2015, Accepted September 14 th 2015 Abstract A case report of nasal polyps in an eight year-old Tabapuã cow is reported. The cow had a history of difficulty in breathing, was euthanatized and referred for necropsy. Twenty three pedunculated neoformations were observed in the nasal cavity. Microscopically, polypoid structures were composed by swollen myxomatous stroma lined by pseudostratified columnar epithelium. Immunohistochemistry was positive for cytokeratin in the cytoplasm of epithelial cells only covering the pseudo-stratified respiratory epithelium, whereas anti-vimentin antibody was positive in the cytoplasm of cells and areas of calcification of the tunica media of blood vessels and fibroblasts within the parenchyma of the polyps. The macroscopy, histopathological, and immunohistochemical findings were consistent with nasal polyps. This is the first report of nasal polyposis in a cow in Brazil. Key words: polyp, bovine, nasopharyngeal obstruction, upper respiratory tract. Introduction Nasal polyps are non-neoplastic structures that rise from the mucosal surface expanding to the nasal cavity, usually due to a chronic inflammatory process (7, 16). Macroscopically, polyps are spherical, ovoid or elongated firm nodules of various sizes, which protrude from the mucosa into the nasal cavity (7, 16). Nasal polyps are initially sessile; however, when larger, they may become pedunculated (2). The surface can be smooth, ulcerated, hemorrhagic and/or present secondary infection (7). Polyps are sometimes multiple and may cause respiratory difficulty due to the obstruction of the nasopharynx (16) and subsequent death due to asphyxiation (13). Histologically, polyps are characterized by edematous fibrous tissue covered by regular respiratory epithelium or stratified squamous epithelium (16) and by a lymphocytic inflammatory infiltrate (7). Clinical signs are not specific; increased respiratory effort, stertorous inspiration, nasal discharge and/or epistaxis are the most clinically observed signs (13, 15). Nasal polyps occur infrequently in animals. In horses, there is a condition called progressive ethmoid hematoma or hemorrhagic nasal polyp. In cats, polyps can affect the ear canal and even the middle ear (2, 16). In goats, nasal polyps have been described as enzootic intranasal tumors (4). Nasal polyposis is one of the disorders less commonly reported in cattle (11). The aim of this article was to describe a case report of nasal polyp in a cow by means of necropsy, histopathology and immunohistochemistry. Case report An eight year-old purebred Tabapuã cow was referred to the Veterinary Pathology service at UNESP (Araçatuba, Brazil), after humane euthanasia. The cow had history of difficulty breathing, and therapy was unsuccessful. Clinical signs started about six months before the death and when the animal was submitted to management, respiratory difficulty was more noticed. The cow presented respiratory sounds that became more severe with time and were audible even at a considerable distance.