Nasopharyngeal polyps are uncommon, benign, smooth, pink, fleshy, pedunculated, inflammatory growths of connective tissue found in the external ear canals of young cats. They arise from the mucosal lining of the tympanic bulla, the pharyngeal mucosa, or the auditory tube. These polyps may be congenital, or they may result from chronic bacterial otitis media, commonly found in cats with upper respiratory diseases. They are rarely found in dogs. They are not neoplastic, and viruses have not been identified in polyp tissue.
Diagnosis involves sedation and deep otoscopic examination of the horizontal canal. Purulent discharge from the bulla may need to be flushed and suctioned from the ear canal to visualize the polyp. Use of a video otoscope greatly facilitates visualization and treatment of polyps. Polyps originating from the eustachian tube may be seen by retracting the soft palate rostrally. Radiography of the bullae may reveal an opacity in the affected bulla. CT or MRI may be helpful if a mass is suspected in the tympanic bulla that cannot be seen otoscopically. Definitive diagnosis is made via histopathology.
Surgical removal is curative as long as the entire polyp and stalk are removed. This often involves performing a bulla osteotomy, because the base of the polyp is often in the tympanic bulla. Incomplete removal of the base of the polyp by traction avulsion alone leads to rapid regrowth and return of clinical signs in 15%–50% of cats. Topical steroids in the bulla for 30–45 days seems to retard this regrowth. Systemic antibiotic therapy for the bacterial otitis media is also indicated.