title: Characteristics of 419 patients with acquired middle ear cholesteatoma.
abstract: BACKGROUND
  Cholesteatoma is a destructive lesion that can result in life-threatening complications. Typically, it presents with hypoacusis and continuous otorrhea as symptoms. Because it is a rare disease, there are few studies in Brazil describing the characteristics of patients with the disease.
  
  
  OBJECTIVE
  This study aimed to determine the prevalence of cholesteatoma in patients with chronic otitis media and describe clinical, audiological and surgical characteristics of patients with acquired middle ear cholesteatoma treated at a referral hospital in the public health system.
  
  
  METHODS
  Cross-sectional and prospective cohort study, including 1710 patients with chronic otitis media, treated between August 2000 and June 2015, without prior surgery. Detailed clinical history, videotoscopy, and audiometry were performed, in addition to review of medical records to search for surgical data. Cholesteatomas were classified according to their route of formation.
  
  
  RESULTS
  Of the patients with chronic otitis media, 419 (24.5%) had cholesteatoma; mean age of 34.49 years; 53.5% female and 63.8% adults. Bilateral cholesteatoma was observed in 17.1%. Anterior epitympanic cholesteatoma corresponded to 1.9%; posterior epitympanic, 32.9%; posterior mesotympanic, 33.7%; two routes, 14.8%; and indeterminate, 16.7%. The mean air-bone gap was 29.84dB and did not differ between routes of formation. There were no correlations between gap size and patient age or duration of symptoms. Of the surgical cases, 16.8% underwent closed tympanomastoidectomy and 75.2% open tympanomastoidectomy.
  
  
  CONCLUSIONS
  The prevalence of cholesteatoma in patients with chronic otitis media was 24.5% and it was more common in adults than in children. Posterior mesotympanic cholesteatoma was more frequent, with no difference in mean air-bone gap between the different routes of formation. In patients undergoing surgery, open tympanomastoidectomy was the procedure most frequently chosen.
authors.affiliation: Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil; Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil. Electronic address: leticiarosito@gmail.com.
authors.forename: Letícia Petersen Schmidt
authors.initials: LP
authors.lastname: Rosito
authors.affiliation: Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil; Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
authors.forename: Maurício Noschang Lopes
authors.initials: MN
authors.lastname: da Silva
authors.affiliation: Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil.
authors.forename: Fábio André
authors.initials: FA
authors.lastname: Selaimen
authors.affiliation: Universidade Federal do Rio Grande do Sul (UFRGS), Faculdade de Medicina, Porto Alegre, RS, Brazil.
authors.forename: Yuri Petermann
authors.initials: YP
authors.lastname: Jung
authors.affiliation: Universidade Federal do Rio Grande do Sul (UFRGS), Faculdade de Medicina, Porto Alegre, RS, Brazil.
authors.forename: Marcos Guilherme Tibes
authors.initials: MG
authors.lastname: Pauletti
authors.affiliation: Universidade Federal do Rio Grande do Sul (UFRGS), Faculdade de Medicina, Porto Alegre, RS, Brazil.
authors.forename: Larissa Petermann
authors.initials: LP
authors.lastname: Jung
authors.affiliation: Universidade Federal do Rio Grande do Sul (UFRGS), Faculdade de Medicina, Porto Alegre, RS, Brazil.
authors.forename: Luiza Alexi
authors.initials: LA
authors.lastname: Freitas
authors.affiliation: Universidade Federal do Rio Grande do Sul (UFRGS), Faculdade de Medicina, Departamento de Oftalmologia e Otorrinolaringologia, Porto Alegre, RS, Brazil.
authors.forename: Sady Selaimen
authors.initials: SS
authors.lastname: da Costa
mesh_terms: D000328:Adult; D001938:Brazil / Q000453:epidemiology; D018424:Cholesteatoma, Middle Ear / Q000453:epidemiology* / Q000209:etiology; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D010033:Otitis Media / Q000150:complications / Q000453:epidemiology*; D015995:Prevalence; D011446:Prospective Studies
keywords: Bilateral; Cholesteatoma; Cirurgia; Classification; Classificação; Colesteatoma; Middle ear; Orelha média; Surgery