Aural Cholesteatoma (Tympanokeratoma) in Veterinary Medicine: An Update and Principles of Clinical Management.

Abstract

BACKGROUND: Aural cholesteatoma (tympanokeratoma) is a destructive epidermoid cyst arising within the temporal bone. In veterinary medicine, it is a historically rare and challenging entity. In recent years, reports of cases in animals have increased, and there is a trend towards minimally invasive approaches that appear promising for better outcomes. HYPOTHESIS/OBJECTIVES: Our objective was to assimilate prior and new knowledge of cholesteatoma epidemiology, aetiology and clinical management in animals. We utilised this information to propose a staging scheme and basic treatment principles for common veterinary species. MATERIALS AND METHODS: Animal cases of cholesteatoma were identified using an advanced PubMed search. Annual incidence in dogs was estimated using previously published figures. Signalment data (breed, age, sex) were summarised for affected dogs and cats. Outcomes were summarised for studies with ≥ 2 cases and ≥ 3 months of follow up data. Previously unpublished cases, including a rabbit with spontaneous disease and a dog managed with radiation therapy, were featured to address literature gaps. RESULTS: Cholesteatoma is reported in > 200 dogs as well as cats, gerbils and rabbits. Brachycephaly and otitis externa appear predisposing in dogs. There may be an emerging association with aural polyps in dogs and cats. There is insufficient evidence to support radiation therapy as a primary treatment modality. Endoscopy-assisted nonsurgical and surgical approaches appear to have lower rates of clinical relapse than conventional surgery. CONCLUSIONS AND CLINICAL RELEVANCE: This is the first work to propose a clinical staging scheme and best practices for treating cholesteatoma in companion animals. Future investigations are needed to validate or improve upon these recommendations.