Successful Diagnosis and Treatment of Naso-Sinual Myxosarcoma in a Dog

Nasal and paranasal sinus tumours are relatively uncommon in dogs, accounting for approximately 1-2% of all canine neoplasms. However, they constitute the majority of tumours affecting the upper respiratory tract in dogs (Withrow et al., 2020). These tumours are predominantly malignant and locally invasive, leading to progressive destruction of surrounding soft tissues and bony structures of the nasal cavity and paranasal sinuses (Thrall and LaRue, 1995). Clinical manifestations commonly include unilateral or bilateral nasal discharge, epistaxis, sneezing, facial deformity, stertor and dyspnoea (Ettinger et al., 2017). Carcinomas are the most commonly reported canine nasal tumours, whereas sarcomas occur less frequently (Meuten, 2017). Myxo-sarcomas are classified as soft tissue sarcomas of fibroblast origin with an abundant myxoid matrix composed of mucopolysaccharides (Meuten, 2017). The prognosis is generally poor because of the high rates of local recurrence and metastasis (Gage et al., 2019). Advanced diagnostic modalities such as rhinoscopy and computed tomography (CT) are important for evaluation of tumour extent, turbinate destruction and sinus involvement (Adams et al., 2009). Histopathological examination remains the gold standard for definitive diagnosis. Therapeutic approaches commonly involve surgery, radiation therapy and chemotherapy either alone or in combination depending upon tumour type and extent of disease (Dernell et al., 1998). The present case report describes the clinical presentation, diagnostic findings, surgical management and chemotherapeutic treatment of naso-sinusal myxosarcoma in a dog.