Bilateral Rostral Maxillectomy for the Treatment of Oral Well-differentiated Fibrosarcoma in a Golden Retriever

A 9-year-old female Golden Retriever was presented for a maxillary mass. The mass was excised for histological examination, showing proliferation of spindle cells. In the referal Veterinary Teaching Hospital of Hokkaido University, intraoral observation under sedation revealed an ulcerative mass arising from the gingiva to external maxillary surface and a swelling of the hard palate. The computed tomography (CT) showed destruction of the maxilla bone and extension of the mass into the nasal cavity. Bilateral rostral maxillectomy was planned according to the CT findings and performed. Histological examination for the surgically resected tissues indicated well-differentiated fibrosarcoma and tumor-free surgical margins. Though the shortening of the upper jaw was apparent, recurrence and metastasis were not observed 25 months after surgery.