Oral Cancer: From Biopsy to Excision

INTRODUCTION

Oral tumors are common in cats and dogs. They may be of dental (odontogenic) or non-dental origin. In dogs, peripheral odontogenic fibroma, acanthomatous ameloblastoma, malignant melanoma, squamous cell carcinoma and fibrosarcoma are most commonly diagnosed in the mouth. In cats, the predominant oral tumors are squamous cell carcinoma and fibrosarcoma. 1

BENIGN LESIONS

Papillomas are viral-induced, cauliflower-like whitish lesions at mucous membranes and mucocutaneous junctions of the mouth. They occur in dogs less than one year of age and often resolve spontaneously in 1-3 months (unless the patient is immunocompromised). Peripheral odontogenic fibromas are mixed odontogenic tumors and are often located in the gingiva near incisor, canine or premolar teeth. The ossifying type (previously called ossifying epulis) is distinguished from the fibromatous type (previously called fibromatous epulis) by containing varying amounts of bone or dental hard tissue within the tumor’s soft tissue. These tumors are excised together with extraction of the involved tooth and thorough curettage of its alveolus. 2 Ameloblastomas are epithelial odontogenic tumors. The canine acanthomatous ameloblastoma (previously called acanthomatous epulis) is a locally invasive tumor causing bone lysis around tooth roots and cystic changes. However, it does not metastasize and is therefore considered to be benign. It often has a rough cauliflower-like surface and may sometimes be similar in appearance to a squamous cell carcinoma. It occurs most commonly in the incisor and canine tooth area of the lower or upper jaw, and less commonly in the carnassial tooth area of the lower or upper jaw. Treatment is mandibulectomy and maxillectomy. 2 Odontomas are not true neoplasms but a conglomerate of disorganized, normal tissue cells. Enamel, dentin, cementum, and small tooth-like structures may compose the mass. Lesions with characteristics resembling normal teeth are considered compound odontomas, whereas complex odontomas have a more disorganized arrangement. Other benign oral tumors that are less common include the inductive fibroameloblastoma (cats only), amyloid-producing odontogenic tumor, osteoma, and lipoma. […]