title: Cholesteatoma of the external ear canal: etiological factors, symptoms and clinical findings in a series of 48 cases.
abstract: BACKGROUND
  To evaluate symptoms, clinical findings, and etiological factors in external ear canal cholesteatoma (EECC).
  
  
  METHODS
  Retrospective evaluation of clinical records of all consecutive patients with EECC in the period 1979 to 2005 in a tertiary referral centre. Main outcome measures were incidence rates, classification according to causes, symptoms, extensions in the ear canal including adjacent structures, and possible etiological factors.
  
  
  RESULTS
  Forty-five patients were identified with 48 EECC. Overall incidence rate was 0.30 cases per year per 100,000 inhabitants. Twenty-five cases were primary, while 23 cases were secondary: postoperative (n = 9), postinflammatory (n = 5), postirradiatory (n = 7), and posttraumatic (n = 2). Primary EECC showed a right/left ratio of 12/13 and presented with otalgia (n = 15), itching (n = 5), occlusion (n = 4), hearing loss (n = 3), fullness (n = 2), and otorrhea (n = 1). Similar symptoms were found in secondary EECC, but less pronounced. In total the temporomandibular joint was exposed in 11 cases, while the mastoid and middle ear was invaded in six and three cases, respectively. In one primary case the facial nerve was exposed and in a posttraumatic case the atticus and antrum were invaded. In primary EECC 48% of cases reported mechanical trauma.
  
  
  CONCLUSIONS
  EECC is a rare condition with inconsistent and silent symptoms, whereas the extent of destruction may be pronounced. Otalgia was the predominant symptom and often related to extension into nearby structures. Whereas the aetiology of secondary EECC can be explained, the origin of primary EECC remains uncertain; smoking and minor trauma of the ear canal may predispose.
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, Aalborg Hospital, Aarhus University Hospital, DK-9000 Aalborg, Denmark. hhowen@dadlnet.dk
authors.forename: Hanne H
authors.initials: HH
authors.lastname: Owen
authors.forename: Jørn
authors.initials: J
authors.lastname: Rosborg
authors.forename: Michael
authors.initials: M
authors.lastname: Gaihede