Colesteatoma del conducto auditivo externo en la infancia

Abstract

Introduction and objective: Congenital aural atresia happens in 1 in 10,000 – 20,000 births, it is generally associated with microtia, and it is the result of an arrest in the embryonic development of the first branchial arch. A possible complication of this entity is acquired cholesteatoma of the external auditory canal (EAC) because of the entrapment of keratinized epithelium. The following case is presented with the aim of making visible a rare entity, influencing its early diagnosis and exposing the surgical treatment to prevent possible complications derived from this condition and avoid its recurrence. Clinical case: We present the case of an 8-year-old male with congenital microtia. The otoscopy shows a narrow and filiform EAC that does not allow its fundus to be visualized, and the liminal pure tone audiometry shows moderate ipsilateral conductive hearing loss. A CT scan of the petrous bones is performed, revealing stenosis of the external third of the bone EAC and soft parts density tissue that completely occupies the EAC and enters the middle ear, partially encompassing the ossicular chain, which is preserved. Surgical intervention was carried out using a retroauricular approach until reaching the stenotic bone duct, reaming it circumferentially, respecting the skin (canaloplasty), finding a duct cholesteatoma, which was removed. The entire tympanic membrane is observed, with normality of the tympanic cavity, and a large meatoplasty is performed. Discussion: The incidence of acquired cholesteatoma of the EAC is low, developing it in approximately 1 in 5 patients with congenital aural atresia. For this reason, clinical suspicion through anamnesis, considering otological malformations, and physical examination with otoscopy are of great importance. This suspicion will guide the performance of a petrous bone CT as the diagnostic imaging test of choice. The treatment of choice is surgery, with excision of the duct cholesteatoma to reduce and try to eradicate its high probability of recurrence, associated with a canaloplasty to widen the EAC by more than 10 mm and a meatoplasty to avoid restenosis. In addition, it is pertinent to perform an exploratory tympanotomy in cases in which middle ear involvement is suspected. Conclusions: Congenital aural atresia can lead to an EAC cholesteatoma as a complication. Its diagnosis is based on clinical suspicion, otoscopy, and petrous bone CT. Its treatment is surgical through exeresis of the cholesteatoma, canaloplasty and meatoplasty and, where appropriate, exploratory tympanotomy.