title: Development of canal cholesteatoma in a patient with prenatal isotretinoin exposure.
abstract: OBJECTIVE
  To describe the clinical and radiologic findings in a case of isotretinoin embryopathy-like syndrome and discuss management of hearing loss, congenital external auditory canal (EAC) stenosis, and EAC cholesteatoma.
  
  
  METHODS
  Review of medical, audiological, and radiological records.
  
  
  RESULTS
  An 8 year old female presented with bilateral moderate conductive hearing loss, bilateral microtia, left EAC stenosis, and right EAC atresia, secondary to prenatal isotretinoin exposure. Comorbidities included developmental delay, ventricular septal defect, hypotonia, and retinal maldevelopment. The left EAC was sharply upsloping with a 2mm-diameter meatus. Computed tomography (CT) scan of the temporal bone demonstrated normal middle and inner ears bilaterally; serial CT scans over 6 years demonstrated progressive development of left canal cholesteatoma. Implantation of a right BAHA system was performed, followed by left canalplasty and excision of cholesteatoma with facial nerve monitoring. An endaural incision was utilized to avoid compromising future microtia repair. Postoperative left-sided hearing improved to mild low-frequency conductive hearing loss rising to normal at 2000 Hz and above.
  
  
  CONCLUSIONS
  Despite extensive precautions for its use, isotretinoin remains a cause of major birth defects, including sensorineural, conductive or mixed hearing loss. Congenital EAC stenosis is much less common than congenital atresia or acquired stenosis; optimal surgical approaches vary depending on hearing status and facial nerve anatomy. Close monitoring for development of canal cholesteatoma is necessary.
authors.affiliation: Thomas Jefferson School of Medicine, USA.
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Van Abel
authors.forename: Marc E
authors.initials: ME
authors.lastname: Nelson
authors.forename: Ryan M
authors.initials: RM
authors.lastname: Collar
authors.forename: Marci M
authors.initials: MM
authors.lastname: Lesperance
mesh_terms: D000014:Abnormalities, Drug-Induced / Q000209:etiology; D002648:Child; D002781:Cholesteatoma / Q000139:chemically induced* / Q000000981:diagnostic imaging / Q000601:surgery; D004423:Ear / Q000002:abnormalities*; D004424:Ear Canal / Q000000981:diagnostic imaging; D004427:Ear Diseases / Q000139:chemically induced* / Q000000981:diagnostic imaging / Q000601:surgery; D005260:Female; D006314:Hearing Loss, Conductive; D006801:Humans; D015474:Isotretinoin / Q000009:adverse effects*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D011859:Radiography; D013723:Teratogens
chemical_list: D013723:Teratogens; D015474:Isotretinoin