Squamous cell carcinoma, developing as an epidermal keratinocytes and indicating various degree of squamous differentiation is a malignant neoplasm. This tumor is one of the most common oral and skin tumors in cats. In the present study, a seventeen years old female and 2.800 g of weight cat was referred to, Surgery Clinic of Veterinary Medicine. The cat was suffering from dysphagia, dyspnea and emaciation. In the physical examination, the cat was found extremely dehydrated. There were shedding for canine, incisive and molar teeth and granulomatous, hemorrhagic and necrotic tissue proliferation in the mucosa of the upper palate. Destruction of bone tissue in the palate and maxillar deformation zone protruding outward was determined. In the histopathological examinations of the biopsy material, there were pleomorphic epithelial cells with excessive eosinophilic cytoplasm containing irregular neoplastic proliferation extends into dermis. Concentric cell reproduction and central keratinization area composed of mature keratinocytes were determined. Small number of keratotic glob corne and large number of parakeratotic glob corne were noticed.

On the radiographic findings, there was a radiolucent area affecting the left side of the hard palate. Canine, premolar and molar teeth shedding were determined due to surrounding tissue destruction. It was noticed that left upper maxillary bone was bulging outward and turbinate pattern of hard palate was destructed. On the lateroabdominal and thoracic radiographs, there were no tumor metastases in the lungs and abdominal organs. History, clinical, radiographic findings and histopathological investigations revealed that the characteristic of mass was oral invasive squamous cell carcinoma.

This report was presented to take consideration of veterinarians that malignant tumor effecting the mouth region might have concealed for a long time.