Exostoses of external ear canal

Objectives: To evaluate (1) patients with external ear canal exostoses by age, sex and participating in water activities; (2) it's influence to hearing loss; to determine the relationship between the obstruction of external auditory canal and (3) the hearing loss; to evaluate (4) histology of external ear canal exostoses. Methods: Data of 20 patients that were operated for external ear canal exostoses in Hospital of Kaunas University of Medicine (Lithuania) since November 2005 to January 2007 were analyzed. Anamnesis data were correlated with otoscopic and operation findings. A simple grading system was devised, based on the degree of external auditory canal stenosis. Grades of mild, moderate, and severe corresponded to 99% to 66%, 65% to 33%, and less than 33% effective patent surface area, respectively. Eliminated bone fragments were evaluated histologically. Results: All 20 patients (100%) were men with the mean age of 49.2 +/- 8.4 years old (35-68 years). Water activities as a risk factor was indicated in 17 (85%) patients. Moderate stenosis of external ear canal was observed in 14 (70%), servere stenosis in 6 (30%) patients. 16 (80%) patients complained of hearing loss. Audiologically conductive or mixed hearing loss was confirmed in 8 (40%) patients. Histology verified remodeled concentric lamellar bony organization without intervening vascular tissue in all (100%) cases. In 3 cases (15%) there were seen Havers canal system and in other 3 samples (15%) lamellar bone was covered with keratotic planocellular epithelium. No statistical corelation was found between the obstruction of external auditory canal and the length of time spent for water activities or hearing loss. Conclusion: In our research exostoses of external ear canal were common in middle-aged men, who complained of hearing loss and recurrent otitis externa. Conductive or mixed hearing loss was confirmed for the half of all patients that complained of hearing loss. A histologic examination showed remodeled concentric lamellar bony organization without intervening vascular tissue. Data of our research correspond to literature data.