Congenital atresia of external auditory canal with choristoma: A rare case report

Abstract

Congenital aural atresia (CAA) is the abnormality of the auricle and/or external auditory canal where there is closure of the external auditory canal which may be associated with microtia and anomalies in the middle ear, inner ear, or temporal bone. It can be solid or membranous type of atresia. To identify the type of defect, high-resolution computed tomography (HRCT) temporal bone is useful. After identifying the defect, the patient can be planned for canaloplasty or atresiaplasty with split skin graft. A 6-year-old boy was brought to the otorhinolaryngology outpatient department with complaints of deformity of the left ear since birth. HRCT temporal bone showed isolated left external auditory canal atresia. Echocardiogram showed dextrocardia with situs solitus and USG abdomen revealed situs inversus of the abdominal organs with no significant abnormality. After proper evaluation of the child, after obtaining preanesthetic fitness, the child had undergone atresiaplasty with split skin graft under general anesthesia. Soft tissue that was excised from the external auditory canal was sent for histopathological examination, which revealed the presence of salivary gland tissue with lymph nodes showing reactive changes. These features were suggestive of possibility of choristoma of the left external auditory canal. CAA occurs in the defect during embryological development which may result in deformity of the auricle and external auditory canal. The surgical management of congenital external auditory canal atresia is atresiaplasty, and hearing rehabilitation (bone anchored hearing aid) should be given in case of no improvement in hearing. The surgery will be challenging because of altered anatomy of surgical landmarks. Choristoma is a tumor-like growth of normal tissue in an abnormal place. It is a benign condition, which may be found commonly in the head-and-neck region such as presence of salivary gland tissue in the middle ear, presence of gastric mucosa in the tongue and presence of osseous or cartilaginous masses in the intraoral soft tissues. Total excision can be done for small and pedunculated tumors, and care should be taken not to injure facial nerve. CAA may not necessarily present with deformities in the external ear (pinna), but Congenital aural atresia cases may not always present with deformities of the pinna,but it is crucial not to miss such cases. These patients may be evaluated by doing High Resolution Computed Tomography temporal bone and audiometric assessment such as. Pediatric evaluation is equally important to rule out for any syndromic association. Atresiaplasty or canaloplasty has shown great result for correcting the cosmetic defect. Hearing can be facilitated further using bone anchored hearing aids or cochlear implantation.