External Auditory Canal Osteoma With Cholesteatoma and Sinus Thrombosis

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.

Spongiotic osteoma in the external auditory canal: Two cases of a rare tumor

Osteoma of the external auditory canal is a rare benign tumor with an estimated incidence of 0.05% of total otologic surgeries. In most cases, an osteoma in the external auditory canal does not cause symptoms because the tumor grows slowly and does not occlude the ear canal. However, if the mass grows to occlude the external auditory canal, several symptoms can occur, including conductive hearing loss, aural fullness, and keratin debris accumulation. We present two cases of this rare tumor in a 23-year-old woman and a 19-year-old man. The mass was surgically excised at the level of the peduncle under local anesthesia with microscope assistance. The base of the excised mass was drilled with a diamond burr to remove all osseous lesions. Histopathologic findings showed spongiotic osteomas. In these cases, patients had symptoms of aural fullness, although the osteomas did not completely occlude the external auditory canal, and the symptoms improved after surgical excision without recurrence.