![]() Hidden large cholesteatoma has been missed out in our patient due to inability to examine an atretic ear canal. More strikingly, they found cholesteatomous developments in 91 % (10 out of 11) patients with ear canal diameters of 2 mm or less. They found 48% of their EAC stenosis patients (with the ear canal smaller than 4 mm diameter) developing cholesteatoma and none of them were under the age of three. Nishimura et al (1985) reported another cholesteatoma case with aural atresia, arising behind the atresia plate that also caused mastoditis and subperiostal abcess 13.Cole and Jahrsdorfer (1990) 14reported the largest series of cholesteatoma and aural stenosis association. ![]() Zalzal et al (1987) reported a case of a two year old boy with congenital aural atresia complicated by acute mastoiditis and lateral sinus thrombosis due to concurrent cholesteatoma 12. This theory is known as “embryological rest” theory and was credited as one of the possible mechanisms of congenital cholesteatoma development 11. The occurrence of latter type is explained by the trapping of the epidermoid elements during the embryological arrest of the EAC formation so as to form a nidus for the cholesteatoma behind the atresia plate 10. Other mode is the development of the cholesteatoma medial to the atretic plate or inside the tympanic cavity. Similar findings were seen in our case with disease limited to right external and middle ear.Ĭholesteatoma formation in atretic ears have two different patterns, one with ear canal of diameter 4 mm or smaller in which cholesteatoma formation is attributed to invagination of small pouch lined with ectoderm within the canal itself. While associated abnormalities of the auricle are common, the inner ear development of these patients is most often normal. It is commonly unilateral, more frequently involving the right ear 9. The dominating feature of congenital aural atresia is absence of the external auditory canal. Arrow pointing to exposed facial nerve (vertical segment) Arrow pointing towards oval window areaįigure 4. (A) Right canal atresia with soft tissue density behind it (B) CT sino-gram showing multiple (arrow marked) sinuses communicating to right middle ear cavity.įigure 3. Middle ear cavity was covered with temporalis fascia graft.įigure 1. Obliteration of mastoid cavity posterior to vertical segment of bony facial canal was done using pedicled temporalis muscle flap to reduce the size of postoperative cavity. Lateral semicircular canal bulge, facial nerve canal and chorda tympani were found at their usual locations ( Figure 4). Oval window area showed bony depression without any overlying stapes footplate ( Figure 3). Except remnant of malleus head which was fixed to epitympanic wall, no other ossicle was found. Cholesteatoma sac was seen filling the mastoid antrum area extending into middle ear cavity and EAC with erosion of posterior canal wall. Intraoperatively, there was right EAC membranous atresia with fistulous opening in cavum conchae. Patient underwent right radical mastoidectomy with wide conchal meatoplasty under general anaesthesia. There was associated erosion of posteroinferior and anteroinferior wall of EAC. These fistulous tracts were communicating through middle ear cavity ( Figure 2B). A CT based fistulogram done four months before our consultation identified multiple fistulous tracts situated in post auricular region and anterior to stylomastoid foramen in inframastoid region. Soft tissue density was seen filling the EAC and the entire middle ear cavity ( Figure 2A). HRCT scan of temporal bones showed membranous atresia of right EAC with grade II microtia. Tuning fork tests using 256 and 512 Hz tuning forks showed moderate to severe conductive hearing loss in right ear with Rinne’s test positive in left ear. Left ear examination was normal with intact tympanic membrane. A small fistulous opening was also seen in right cavum conchae region. On local examination, there was right Grade II 8microtia with atretic External Auditory Canal (EAC) and pre-auricular skin tag ( Figure 1). She had a history of incision and drainage in right post auricular area six months prior for similar complain. A 13 year old girl presented in ENT outpatient department with complains of recurrent right ear purulent discharge from pre and post auricular area for last 5 years.
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