Inflammatory / infectious / autoimmune / systemic disorders

Topic Completed: 01 October 2013

Revised: 07 January 2019

Copyright: (c) 2002-2019, PathologyOutlines.com, Inc.

PubMed Search: Otosclerosis [title] review[ptyp]

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Cite this page: Pernick N. Otosclerosis. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/earotosclerosis.html. Accessed January 22nd, 2019.
Definition / general
  • Disorder of bone remodeling affecting bony labyrinth and stapes footplate
  • Does not appear to occur outside temporal bone (Am J Otol 1999;20:162)
  • Causes fixation of stapes footplate in oval window and inability to transmit sound waves manifesting as conductive hearing loss
  • Usually women; 50% have family history; begins in teenagers and slowly progresses
  • More common in whites than blacks, Asians or Native Americans
  • Associated with measles virus (Ann Otol Rhinol Laryngol 2001;110:897)
  • 85% bilateral
  • Stapedectomy (correction of fixation of footplate of stapes)
Gross description
  • Specimens are usually head and crura of stapes which are not affected by disease
Microscopic (histologic) description
  • Initially bone resorption and replacement by cellular fibrovascular tissue around blood vessels; then immature bone is deposited with continuous resorption and remodeling; over time, bone is deposited with increased collagen and reduced ground substance resulting in densely sclerotic bone with prominent cement lines