Inflammatory / infectious / autoimmune / systemic disorders

Otitis media

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Last staff update: 15 December 2020

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Nat Pernick, M.D.
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Cite this page: Pernick N. Otitis media. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/earotitismedia.html. Accessed June 3rd, 2023.
Definition / general
  • Acute or chronic infectious disease of middle ear
  • Usually childhood disease caused by Streptococcus pneumoniae or Haemophilus influenzae (Pediatr Infect Dis J 2004;23:1142); also coinfection by viruses (Clin Infect Dis 2006;43:1417)
  • Rarely caused by fungi or Pneumocystis in HIV+ patients
  • Hyperemic, opaque and bulging tympanic membrane with limited mobility; may have purulent otorrhea
  • Infection probably occurs post pharyngitis via eustachian tube
  • Severe cases are associated with destruction of ossicles
  • Tympanosclerosis: dystrophic calcification of tympanic membrane or middle ear associated with recurrent cases of otitis media, occurs in 3 - 33% of cases; may be reversible in children, usually irreversible in adults and associated with conductive hearing loss
Gross description
  • Not a common specimen, but may have small fragments of soft / rubbery granulation tissue
Microscopic (histologic) description
  • Acute and chronic inflammatory cells, haphazard glandular metaplasia (Laryngoscope 1982;92:273) with cilia, fibrosis, hemorrhage, foci of calcification (tympanosclerosis), cholesterol granulomas and reactive bone formation
  • Cholesterol granulomas: foreign body granulomas in response to cholesterol crystals from rupture of red blood cells and breakdown of lipid bilayer in cell membrane, prominent cholesterol clefts; associated with interference to drainage or ventilation of middle ear space; not related to cholesteatomas
Differential diagnosis
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