Primary neoplasms of the nasal cavity, paranasal sinuses and nasopharynx in the dog. A report of 16 cases from the files of the AFIP.

Sixteen cases of primary neoplasms of the nasal cavity, paranasal sinuses and nasopharynx in the dog were reviewed from the files of the Armed Forces Institute of Pathology (AFIP). The mean age of affected dogs was 9.5 years. The presenting clinical signs were epistaxis, nasal discharge or facial swelling. Eleven of the affected dogs were purebred. Three of these were Collies and two German Shepherds. The nasal cavity was involved most often. All neoplasms were malignant (11 carcinomas and five sarcomas), and there was invasion of the adjacent bony structures in most dogs. Tumors were classified according to prominent cell type and degree of differentiation into respiratory epithelial carcinoma (four), adenocarcinoma (one), squamous cell carcinoma (one), mucoepidermoid carcinoma (two), undifferentiated carcinoma (three), chondrosarcoma (three) and undifferentiated sarcoma (two).