Oropharyngeal Adenosquamous Carcinoma in a Dog

Abstract

A 13-year-old male Cavalier King Charles Spaniel weighing 5.7 kg developed weight loss and exercise-induced breathing difficulty. Visual examination under general anesthesia revealed a plaque-like oropharyngeal mass measuring 5×3 cm. The mass occupied the oropharynx between the soft palate and the buccal mucosa bilaterally; however, the tonsils were unaffected. Following debulking surgery, the dog developed cardiac arrest and could not be resuscitated. A postmortem examination was performed. Histopathological examination of the mass, as well as lymph node and lung specimens revealed a characteristic pattern of infiltrating adenocarcinoma concomitant with squamous cell carcinoma, and the dog was diagnosed with stage IV oropharyngeal adenosquamous carcinoma (ASC). ASC should be considered in the differential diagnosis of oropharyngeal tumors in dogs.