Diagnosis and therapy of polypoid tracheobronchitis presenting as a mass in a dog

Abstract

A 9-year-old Maltese dog was presented with a history of chronic cough. On the radiographic and CT studies a long smoothly marginated tracheal mass with bilateral bronchial extension was detected. These findings were confirmed by bronchoscopy and dynamic grade II tracheal collapse was also observed. Biopsies were performed and histopathology revealed marked polypoid proliferation of the tracheal mucosa with intense lymphoplasmacytic and macrophagic infiltration consistent with polypoid tracheobronchitis. Prednisone was started but due to the absence of a complete response, cyclosporine was added. Six weeks later the cough had resolved, and the mass was not visible at radiographic follow-up. Prednisone was discontinued without recurrence, but when cyclosporine was tapered, the mass and clinical signs reappeared. Three years later the patient was still on treatment with cyclosporine, without clinical signs and no evidence of the mass was observed at the follow-up CT scan.