Congenital Cholesteatoma with Mastoid and Temporal Epidural Abscess in a Patient with Congenital Aural Atresia and Grade II Microtia: A Case Report

Congenital cholesteatoma arising in an ear with congenital aural atresia is a rare entity, and diagnosis is difficult because the atretic plate prevents otoscopic assessment of the tympanic membrane. A 17-year-old male with left grade II microtia and congenital aural atresia presented with worsening left-sided headache, fever, severe mixed hearing loss, and recurrent purulent discharge from a left retroauricular fistula. Temporal computed tomography and contrast-enhanced magnetic resonance imaging showed chronic otomastoiditis with an extensive cholesteatoma eroding the temporal bone, destroying the tegmen tympani, and forming a mastoid abscess extending into the left temporal epidural space. A combined procedure was performed, comprising craniotomy with abscess evacuation and pericranial dural grafting by neurosurgery together with subtotal petrosectomy and abdominal fat obliteration by otolaryngology. Intraoperatively the ossicular chain was fused and no continuity was found between the cholesteatoma matrix and external canal skin, supporting a congenital origin. Culture grew Proteus mirabilis. Symptoms resolved initially, but retroauricular discharge recurred five months postoperatively, after which the patient was lost to follow-up. Congenital aural atresia conceals cholesteatoma from clinical examination, so cross-sectional imaging carries the diagnosis. Disease of this extent warrants structured long-term surveillance.