Mixoma oral em um bovino
Pinto, Maria Helena BarrosBlume, Guilherme ReisMedeiros, Jussara TeixeiraBilego, Ubirajara OliveiraSantAna, Fabiano José Ferreira de
Background: Myxoma is a benign neoplasm of mesenchymal cells producing a myxomatous matrix rich in mucopolysaccharides. This tumor occasionally has been described in older dogs and cats, and rarely occurs in other species. In ruminants myxomas can be found in the rumen and omasum, but there are no reports of these neoplasms involving the oral cavity of cattle. Only one case of myxoma was diagnosed in a 40-year study of 606 neoplasms in cattle in South Africa. Similar retrospective studies done in cattle from southern and northeastern Brazil also detected a single case of cutaneous myxoma. The current study reports the clinical and pathological findings of a rare occurrence of bovine oral myxoma.Case: A 22-month-old male crossbreed steer (Bosindicus) from the municipality of Rio Verde, GO (17°44′42″S 50°55′00″W), Brazil, presented a history of sialorrhea. There is no another affected animal in the herd. Clinical evaluation revealed mild swelling in the lower incisive gum. Treatment with flumetasone IM for three consecutive days was performed. Two months after this procedure, there was a considerable increase in the size to a flat, firm mass of 16x13x9 cm. Other clinical signs included emaciation and severe difficulty in feeding and drinking water. After surgical excision, fragments of the tumor were collected for histopathology. There is no local recurrence within approximately one year of the surgery. Microscopically, the lamina propria was found to be expanded and replaced by a nonencapsulated, moderately cellular, poorly demarcated, neoplastic proliferation. The lesion was composed of numerous loosely arranged bundles of cells in an abundant myxoid matrix. The bulk of the tumor parenchyma was formed by spindle or stellate cells with poorly demarcated borders and scant, eosinophilic cytoplasm. The nuclei were oval and hyperchromatic. Mild anisocytosis and anisokaryosis were present, along with rare mitotic figures.[...](AU)
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