Sinonasal Osteosarcoma in a Horse
Background: Osteosarcomas are common malignant bone tumors described in dogs, humans and cats. However, there are rare reports in horses. The tumor etiology has not been fully elucidated. Clinical signs are associated to the tumor size, location and growth characteristics. When located on the face, the most common findings are facial distortion, nasal discharge and inspiratory dyspnea. The aim of this study was to report an osteoblastic osteosarcoma in a horse, located on the right maxillary region with projections into the corresponding nostril.
Case: A 6-year-old mixbreed saddle gelding, presenting bay coat was admitted to a University Hospital with a chronic sinusitis history. The animal was previously examined and treated by other veterinarians, who suspected of odontogenic maxillary sinusitis, and therefore a repulsion of the fourth premolar from the right maxilla hemiarcade was performed. However, an improvement of the clinical signs was not observed and subsequently the gelding was referred to a Veterinary Hospital. During physical examination the patient presented dyspnea, tachypnea and tachycardia. An increase on the face size was observed, together with a fetid and purulent nasal discharge. During oral cavity inspection, a diagonal wear was detected at the occlusal surface of the right hemiarcade; food accumulation was seen at the dental extraction site, and a communication with the rostral maxillary sinus was evidenced, from where a purulent fetid discharge was draining. At the radiographic exam, well defined margins of a tumor were observed, with adjacent bone lysis and the presence of a central nucleus showing a gross granular mineral radiopacity, distorting the frontal and nasal bones. During the endoscopic exam, a mass was partially occluding the right nasal cavity close to the nasal opening, which was blocking the progression of the endoscopy. However, during the left cavity inspection, at the end of the nasal septum a mass with irregular surface was detected emerging from the border of the right choana, which extended up to the nasopharynx region. The diagnosis was established based on clinical evaluation and histopathological findings of the tumor, which confirmed osteoblastic osteosarcoma. The animal was euthanized due to poor clinical conditions and prognosis. There was no evidence of metastasis to other organs during necropsy.
Discussion: The majority of reported osteosarcoma cases in horses do not define the tumor histopathological subtype. The occurrence of metastasis in equine osteosarcoma is not well established, however it seems to be uncommon. It is important to emphasize the relevance of performing a necropsy in patients presenting osteosarcoma, in order to establish a pattern concerning the metastasis incidence in the species. The predominant osteosarcoma location is the mandible, although there are few reports in the paranasal sinuses and appendicular skeleton. The tumor usual location makes the treatment difficult because of the impossibility of performing a complete surgical resection, which leads to a euthanasia decision. Although osteosarcoma has been little reported in horses, it should be a differential diagnosis for facial alterations and paranasal sinuses abnormalities, which would contribute to an early diagnosis and increase the chances of a favorable prognostic.
Bush J.M., Fredrickson R.L. & Ehrhart E.J. 2007. Equine osteosarcoma: a series of 8 cases. Veterinary pathology. 44(2): 247-249.
Cançado R.D. & Chiattone C.S. 2002. Anemia de Doença Crônica. Revista Brasileira de Hematologia e Hemoterapia. 24(2): 127-136.
Cilliers I., Williams J., Carstens A. & Duncan N.M. 2008. Three cases of osteoma and an osseous fibroma of the paranasal sinuses of horses in South Africa. Journal of the South African Veterinary Association. 79: 185-193.
Cissell D.D., Wisner E.R. & Textor J. 2012. Computed tomographic appearance of equine sinonasal neoplasia. Veterinary Radiology and Ultrasound. 53 (3): 245-251.
Cousty M. & Tricaud C. 2014. Oncology Virtual Issue Articles. Equine Veterinary Education. 26(5): 269-269.
Dimopoulou M., Kirpensteij J., Moens H. & Kik M. 2008. Histologic prognosticators in feline osteosarcoma: a comparison with phenotypically similar canine osteosarcoma. Veterinary Surgery. 37(5): 466-471.
Fowles J.S., Brown K.C., Hess A.M., Duval D.L. & Gustafson D.L. 2016. Intra- and interspecies gene expression models for predicting drug response in canine osteosarcoma. BMC Bioinformatics. 17 (1): 1-14.
Hanna A., Stieger-Vanegas S.M. & Heidel J.R. 2015. Nasal Adenocarcinoma in a Horse with Metastasis to Lung , Liver , and Bone and Review of Metastasis in Nine Horses with Sinonasal Tumors. Case Reports in Veterinary Medicine. (2015). Article ID 845870.
Hauben E.I., Weeden S., Pringle J. & Marck E.A. 2002. Does the histological subtype of high-grade central osteosarcoma influence the response to treatment with chemotherapy and does it affect overall survival ? A study on 570 patients of two consecutive trials of the European Osteosarcoma Intergroup. European Journal of Cancer. 38: 1218-1225.
Head K.W. & Dixon P.M. 1999. Equine nasal and paranasal sinus tumours. Part 1: review of the literature and tumour classification. Veterinary Journal. 157(3): 261-278.
Jenner F. 2010. Osteosarcoma in Equidae. Equine Veterinary Education. 22(3): 130-131.
Jenner F., Solano M., Gliatto J., Lavallee S. & Kirker-Head C. 2003. Osteosarcoma of the tarsus in a horse. Equine Veterinary Journal. 35(2): 214-216.
Kilcoyne I., Wilson M., Terzo E. & David F. 2010. Osteosarcoma of the proximal radius in a donkey. Equine Veterinary Education. 22(3): 125-129.
Koch E., Pack L., Zwicker L.A., Lopez-Mendez C. & Aburto E.M. 2014. Osteosarcoma in the proximal humerus of a mare. Equine Veterinary Education. 26(8): 410-415.
Lee E.S. 1975. Osteosarcoma: a reconnaissance. Clinical Radiology. 26: 5-25.
Meyer F.R.L. & Walter I. 2016. Establishment and Characterization of New Canine and Feline Osteosarcoma Primary Cell Lines. Veterinary Sciences. 3(2): 1.
Springer T., Elce Y.A. & Green E. 2010. Treatment of an osteoblastic osteosarcoma in an aged gelding. Equine Veterinary Education. 22(4): 159-162.
Vanel M., Blond L. & Vanel D. 2013. Imaging of primary bone tumors in veterinary medicine: Which differences?. European Journal of Radiology. 82(12): 2129-2139.
Vieira C.R., Fredo G. & Boabaid F.M. 2014. Osteossarcoma osteoblástico na cavidade nasal de um equino. In: VII Encontro Nacional de Diagnóstico Veterinário (Cuiabá, Brasil). pp.2-3.
Witte T.H. & Perkins J.D. 2011. Early diagnosis may hold the key to the successful treatment of nasal and paranasal sinus neoplasia in the horse. Equine Veterinary Education. 23(9): 441-447.
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