ABSTRACT

The significance of the presence of the mastoid antrum is due to its position as an important landmark in the surgical approach to the mastoid.The mastoid antrum is the largest air cell and communicates anteriorly with the attic through an opening called aditus. It is relatively constant bilaterally even in cases of chronic otitis media. Absence of the mastoid antrum may cause severe complications in mastoid surgery. In the English literature, there is only one case of unilateral agenesis of the mastoid antrum in an adult without any congenital abnormality. A healthy 33-year-old male presented to the Department of Otorhinolaryngology with a history of bilateral, intermittently discarging ears. Examination revealed bilateral large central perforations. Pure tone audiometry showed bilateral 28 dB conductive hearing loss across the frequency range. A preoperative computed tomography (CT) scan demonstrated absence of the antrum and a prominent Körner’s septum bilaterally. It may be absent only in congenital malformations. In our case, there was no congenital abnormality, but bilateral mastoid antrums were absent. We present the first case of bilateral agenesis of the mastoid antrum without any association with a congenital syndrome. (JAREM 2012; 2: 24-6)

Keywords: Mastoid antrum, agenesis, mastoidectomy, ear surgery, Körner’s Septum, chronic otitis