Successful carboplatin chemotherapy for oral fibrosarcoma in the buccal mucosa of a dog

Abstract

An 11-year-old castrated male cocker spaniel presented with halitosis, anorexia, and swelling of the left face. Upon physical examination, a firm mass was detected in the left buccal mucosa. Fine needle aspiration cytology revealed a malignant tumor of mesenchymal origin. We performed biopsy, which gave a diagnosis of oral fibrosarcoma. The client refused surgical treatment, and carboplatin chemotherapy (300 mg/m2, IV, q 21 days) was initiated. The mass gradually decreased in size and disappeared about 89 days after the initial chemotherapy. Complete remission was attained, and the tumor did not relapse. This case report shows that a single carboplatin chemotherapy session can achieve macroscopic complete remission of oral fibrosarcoma.