Benign Osteonecrosis of the External Auditory Canal: Diagnostic Challenges and Outcomes in a Case Series

Introduction Benign osteonecrosis (BON) of the external auditory canal (EAC) is a rare and under recognised otological condition characterised by localised bony necrosis of the tympanic plate. It represents a diagnostic challenge due to its clinical overlap with necrotising otitis externa (NOE), EAC malignancy, keratosis obturans, and other external ear pathologies. Risk factors include antiresorptive pharmacotherapy, particularly bisphosphonates and denosumab, hearing aid use, local mechanical trauma, haemodialysis, and smoking. This retrospective case series aims to characterise the clinical presentation, investigative findings, management strategies, and outcomes of patients diagnosed with BON at a single UK ENT centre. Methods A retrospective review was conducted of seven patients diagnosed with BON of the EAC at the ENT Outpatient Clinics, Tameside General Hospital, between January 2023 and December 2025. Inclusion criteria required a confirmed diagnosis based on clinical examination, histopathological biopsy, microbiological culture, and high-resolution computed tomography (HRCT) of the temporal bones. Data on patient demographics, presenting symptoms, risk factors, investigations, management, and follow-up outcomes were collected and analysed. Results Seven patients (four male, three female; median age 67 years, range 55-80) were included. None had diabetes mellitus. Three patients (43%) had received bisphosphonate therapy for three to five years. Three patients used hearing aids. One patient had chronic kidney disease requiring haemodialysis, and one presented with bilateral disease. All patients underwent HRCT temporal bone imaging and histopathological biopsy. Biopsy confirmed chronic inflammation and bony sequestrum without malignancy or features of NOE in all cases. All seven patients were managed conservatively with serial aural debridement and topical antimicrobial therapy. Progressive epithelialisation was achieved in all patients over a follow-up period of three to eight months. No patient required surgical intervention or hyperbaric oxygen therapy.  Conclusions BON of the EAC is an underreported condition that can be successfully managed conservatively in the majority of cases. Clinician awareness is essential, particularly in patients receiving antiresorptive agents or using hearing aids. Exclusion of malignancy and NOE through biopsy and HRCT imaging is mandatory. Further prospective research is required to establish standardised diagnostic criteria and management guidelines.