Clinicopathological characterization of sinonasal sarcomas in dogs.

The nasal cavity and paranasal sinuses comprise various tissues that can give rise to different neoplasms, including nasal sarcomas. The aim of this study was to describe the clinicopathological characteristics of canine sinonasal sarcomas. A retrospective study was conducted on 39 dogs, aged between 2 and 18 years old, with a diagnosis of sinonasal sarcoma. The dogs were grouped according to tumour type: 12 nasal chondrosarcomas, 12 osteosarcomas and 15 spindle cell tumours (fibrosarcoma, undifferentiated sarcoma, haemangiosarcoma, myxosarcoma and leiomyosarcoma). Most dogs were mixed breed and there was a predominance of large breeds in the cases of nasal osteosarcoma. Facial deformity, epistaxis and dyspnoea were the most common clinical signs. The tumours affected mainly the nasal region. Metastases were uncommon and found in three cases of nasal spindle cell tumour and one case of chondroblastic osteosarcoma. Furthermore, nasal spindle cell tumours had an increased mitotic index, compared with chondrosarcoma and osteosarcoma, suggesting malignancy.