Large osteoma of the external auditory canal

Factors Related to Cholesteatoma Formation in External Auditory Canal Osteomas and Treatment Algorithm

Objectives: Osteomas in the external auditory canal (EAC) can lead to stenosis, and impair epithelium migration and self-cleaning capability, thereby trapping keratinized epithelium and triggering the development of cholesteatoma. Our study aims to identify the risk of cholesteatoma development in patients with osteoma and proposes a stepwise approach to managing patients with EAC osteoma. Methods: The maximum diameter of the osteoma was measured in axial and coronal views on high-resolution computed tomography (HRCT). We calculated the relative obstruction ratio caused by the osteoma in the axial and coronal views. Prior to surgery, otoscopy was employed to identify pedicle formation. The patients were categorized into 2 groups based on the presence of cholesteatoma. Results: We identified 43 patients diagnosed with EAC osteoma. A total of 9 (20.9%) patients with EAC osteomas developed cholesteatoma and the other 34 (79.1%) did not. The maximum diameter of osteomas with and without cholesteatoma was 12.67 ± 4.09 and 7.67 ± 3.27 mm, respectively (P < .001). In the group without cholesteatoma, 21 osteomas had pedicles while the other 13 did not. In the cholesteatoma group, 2 osteomas had pedicles and 7 did not (P = .037). No difference was observed in the relative obstruction ratio between these 2 groups. Conclusions: Our findings indicate that larger osteomas are more likely to develop cholesteatoma, while the formation of a pedicle may reduce the occurrence of cholesteatoma. In symptomatic patients, preoperative evaluation, including HRCT and otoscopy, is vital for assessing the extent of the osteoma and the potential coexistence of cholesteatoma. These factors are critical for preoperative consultations and surgical planning.

Endoscopic transcanal removal of external auditory canal osteomas

Background

External auditory canal (EAC) osteomas are rare, slow-growing benign neoplasms. Microscopic surgical excision had been reported for symptomatic osteomas. However, there was no study published on the feasibility of transcanal endoscopic ear surgery (TEES) for EAC osteoma. In this study, we propose two methods of TEES for symptomatic EAC osteomas and report the surgical outcomes of our patients.

Methods

Fifteen patients diagnosed with symptomatic EAC osteoma who underwent TEES were recruited at two otolaryngology referral centers. The extent of osteoma and degree of EAC stenosis was calculated based on high-resolution computed tomography (HRCT) imaging. We divided all the patients into two groups, solitary pedunculated osteoma or broad-based osteomas. The postoperative outcomes and complications were recorded for at least 6 months of outpatient follow-up.

Results

In this study, twelve patients with solitary osteoma underwent the first method, a direct transcanal removal procedure. In this approach, only a small bare bony area remained postoperatively, and it healed completely within 1 month. Three patients with broad based osteoma underwent the second method, a transcanal approach involving a skin flap. The degree of stenosis in all patients ranged from 29% to 90%. All of them could be treated completely through a transcanal endoscopic approach. No intraoperative or postoperative complications were noted during follow-up, and no canal stenosis and no recurrences were noted during at least 6 months of follow-up.

Conclusions

This endoscopic transcanal approach to EAC osteomas demonstrated good results for lesion removal without recurrence or intraoperative complications.