A case of odontogenic myxoma in a cow

Tumours of odontogenic origin are rare in domestic animals. A case of odontogenic myxoma was recorded in 12 years old cow involving the periodontal region of the left mandible. Tumorous growth was slow growing but progressively increased, locally invasive and recurred after surgical removal. Grossly, the growth was soft and slimy. Histopathologically, it revealed myxoma characterized by large, stellate or triangular fibroblast like cells with cytoplasmic processes, vesicular nuclei and small nucleoli. Mitotic figures were rarely observed. Expression of anti-pancytokeratin and anti-p53 antibodies by immunohistochemistry was not detected. Based on anatomical location, radiographic, gross and histopathological examination, this tumour was diagnosed as an odontogenic myxoma.