Osteoma of the internal auditory canal

Abstract

We present a case of an osteoma of the internal auditory canal, which was surgically removed with symptomatic improvement. We describe CT, MRI, histological and operative findings, with a review of the proposed aetiology. The implications for imaging in the investigation of retrocochlear lesions are discussed.

Osteoma of the Internal Auditory Canal Mimicking Vestibular Schwannoma: Case Report and Review of 17 Recent Cases

“…Six cases were identified incidentally (12%), including our case which was asymptomatic in the affected side at detection, 7 cases had subjective or objective hearing loss (41%), 10 cases had tinnitus and/or aural fullness of the affected side (59%), 11 cases had vertigo and/or dizziness (including past medical history) (65%), and 2 cases had facial palsy (including past medical history) (12%). Several causes have been proposed for IAC osteoma, such as trauma, infection, inflammation, hormones, and constant vascular irritation (Clerico et al 1994;Wright et al 1996;Baik et al 2011), but no apparent risk factors were observed in this review. These results suggest that the rate of incidentally diagnosed cases continues to be high, the predilection for postmenopausal women is not so remarkable, and the risk factors for IAC osteoma remain unclear.…”

“…A previous review of 13 cases of IAC osteoma reported from 1882 to 1993 identified several clinical characteristics as follows: mean age of 57 years; female-to-male ratio of 5.5:1, suggesting a particular predilection for postmenopausal women; and 42% of the patients had no symptoms, 42% had hearing loss, 25% had tinnitus, and 33% had vertigo (Clerico et al 1994). Our present study summarized and reviewed 17 cases of IAC osteoma reported in the past 22 years (1992-2013) (Singh et al 1992;Ramsay and Brackmann 1994;Coakley et al 1996;Wright et al 1996;Boedts et al 1997;Davis et al 2000;Vrabec et al 2000;Kovacić et al 2001;Gerganov et al 2008;Liétin et al 2010;Baik et al 2011;Kaymakci et al 2012;Plantone et al 2013) and excluded the previously reviewed cases by Clerico et al (1994) (Table 1). Mean age was 44.1 years (male: 44.0, female: 44.2), and femaleto-male ratio was 1.4:1.…”

“…Bony stenosis of the IAC is easily recognized on CT imaging, and results from various pathologies: bony tumors within the IAC, such as osteomas and exostoses; generalized enlargements of the temporal bone caused by Paget's disease, fibrous dysplasia, and osteopetrosis; and congenital abnormalities (Clerico et al 1994;Wright et al 1996;Baik et al 2011). IAC osteomas and exostoses are usually slowgrowing tumors, and the differential diagnosis is sometimes difficult to establish.…”

Bilateral osteomas and exostoses of the internal auditory canal

“…Three out of 17 cases of osteoma and 3 out of 4 cases of exostoses were bilateral in nature (Table 2) [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. Symptomatic patients presented at average age of 50 with an average symptom duration of 6.4 years.…”

Osteoma of the Internal Auditory Canal

“…This method of diagnosis is available for 4 reported osteomas. [9][10][11][12] alone. 13,14 Two cases are reported based on radiographic appearance alone.…”