Clinico-pathological characteristics of canine gingival squamous cell carcinoma

In the present study, a case of gingival squamous cell carcinoma is described in a 9-yearold sheepdog with a swelling of the left mandible. Plain radiographs of the head revealed a soft tissue mass behind the ventral border of the left mandible. At necropsy, the tumor presented as reddish-brown ulcerated and irregular tumoral masses of the gingiva. In the cytology smear, there were oval to angularshaped squamous epithelial cells with varying immaturity and variable staining and nuclear to cytoplasmic ratios (N:C). Some of the cells showed dyskeratosis. Histopathologically, the tissue sections were composed of the cords and islands of squamous epithelial cells with an abundant eosinophilic cytoplasm, large and ovoid nuclei with a prominent nucleolus. The mitotic figures were moderate. Based on the histopathological findings, the tumor was diagnosed as a moderately differentiated gingival squamous cell carcinoma.