Akihiro Imai1, Hirotaka Kondo2, Tsunenori Suganuma3, Masahiko Nagata1. 1. Dermatology Service, Synergy Animal General Hospital, 815 Ishigami, Kawaguchi, Saitama, 333-0823, Japan. 2. Laboratory of Veterinary Pathology, Department of Veterinary Medicine, College of Bioresource Science, Nihon University, 1866 Kameino, Fujisawa, Kanagawa, 252-0880, Japan. 3. Diagnostic Image Service, Synergy Animal General Hospital, 815 Ishigami, Kawaguchi, Saitama, 333-0823, Japan.
Abstract
BACKGROUND: Aural cholesteatomas, also called tympanokeratomas, are destructive and expansile growths of keratinizing epithelium that develop in the middle ear. They have been reported sporadically in dogs, and surgery is usually the recommended treatment. OBJECTIVES: To describe the common clinical, radiological and histological findings of cholesteatoma; to report on the outcome of conservative management. ANIMALS: Eleven dogs (13 ears) with cholesteatomas. METHODS AND MATERIALS: Medical records were reviewed for dogs diagnosed with cholesteatoma between 2012 and 2018. All dogs had computed tomography (CT) and/or magnetic resonance imaging (MRI) followed by trans-canal endoscopic procedure (TEP) for removal and biopsy of middle ear lesions. Dogs were then treated with in-clinic flushing initially weekly tapered to monthly, as well as at-home ear cleaning and application of topical otic steroid medication, initially daily then tapered to once or twice weekly. RESULTS: Nine dogs had a history of chronic otitis externa; head tilt or facial paralysis was present in seven and four cases, respectively. Otic examination identified a protruding nodule in seven ears. CT demonstrated soft tissue-like material in 12 bullae and expansion in seven bullae. MRI revealed minimally contrast-enhancing bulla contents in 12 ears. Post-TEP and with maintenance medical treatment, nine ears had no further signs of middle ear disease during a mean follow-up of 27.9 months. CONCLUSIONS AND CLINICAL IMPORTANCE: The results suggest that otitis externa may not necessarily precede cholesteatoma in all dogs. MRI appears to be more sensitive than CT for identifying cholesteatomas. Conservative treatment of cholesteatomas could be useful before or as an alternative to surgery.
BACKGROUND:Aural cholesteatomas, also called tympanokeratomas, are destructive and expansile growths of keratinizing epithelium that develop in the middle ear. They have been reported sporadically in dogs, and surgery is usually the recommended treatment. OBJECTIVES: To describe the common clinical, radiological and histological findings of cholesteatoma; to report on the outcome of conservative management. ANIMALS: Eleven dogs (13 ears) with cholesteatomas. METHODS AND MATERIALS: Medical records were reviewed for dogs diagnosed with cholesteatoma between 2012 and 2018. All dogs had computed tomography (CT) and/or magnetic resonance imaging (MRI) followed by trans-canal endoscopic procedure (TEP) for removal and biopsy of middle ear lesions. Dogs were then treated with in-clinic flushing initially weekly tapered to monthly, as well as at-home ear cleaning and application of topical otic steroid medication, initially daily then tapered to once or twice weekly. RESULTS: Nine dogs had a history of chronic otitis externa; head tilt or facial paralysis was present in seven and four cases, respectively. Otic examination identified a protruding nodule in seven ears. CT demonstrated soft tissue-like material in 12 bullae and expansion in seven bullae. MRI revealed minimally contrast-enhancing bulla contents in 12 ears. Post-TEP and with maintenance medical treatment, nine ears had no further signs of middle ear disease during a mean follow-up of 27.9 months. CONCLUSIONS AND CLINICAL IMPORTANCE: The results suggest that otitis externa may not necessarily precede cholesteatoma in all dogs. MRI appears to be more sensitive than CT for identifying cholesteatomas. Conservative treatment of cholesteatomas could be useful before or as an alternative to surgery.