Editing Cholesteatoma (section)

=== Acquired cholesteatoma ===
More commonly, keratin accumulates in a pouch of tympanic membrane which extends into the middle ear space. This abnormal folding or 'retraction' of the tympanic membrane arises in one of the following ways:
* Jackler's theory: Mucosal coupling with traction generated by interaction of migrating opposing surfaces leading to formation of cholesteatoma.<ref>{{Cite journal |last1=Jackler |first1=Robert K. |last2=Santa Maria |first2=Peter L. |last3=Varsak |first3=Yasin K. |last4=Nguyen |first4=Anh |last5=Blevins |first5=Nikolas H. |date=August 2016 |title=A new theory on the pathogenesis of acquired cholesteatoma: Mucosal traction |url=https://pubmed.ncbi.nlm.nih.gov/26013635/ |journal=The Laryngoscope |volume=125 |issue=Suppl 4 |pages=S1–S14 |doi=10.1002/lary.25261 |issn=1531-4995 |pmid=26013635|s2cid=26340883 }}</ref>
* Wittmaack's theory: Invagination of tympanic membrane from the attic or part of pars tensa in the form of retraction pockets lead to the formation of cholesteatoma.<ref name=ent>{{cite web |vauthors = Becvarovski Z |title=Chronic suppurative otitis media|url=http://www.ent.com.au/CHRONIC%20EAR%20INFECTIONS%20Mar%202003.htm |publisher=ENT |access-date=12 January 2013 |archive-url=https://web.archive.org/web/20130118151857/http://www.ent.com.au/CHRONIC%20EAR%20INFECTIONS%20Mar%202003.htm |archive-date=18 January 2013 |url-status=dead}}</ref>
* Ruedi's theory: The basal cells of germinal layer of skin proliferate under the influence of infection and lay down keratinising [[squamous epithelium]].<ref>{{cite journal |vauthors = Ruedi L |title = Cholesteatoma formation in the middle ear in animal experiments |journal = Acta Oto-Laryngologica |volume = 50 |issue = 3–4 |pages = 233–240; discussion 240–242 |year = 1959 |pmid = 13660782 |doi = 10.3109/00016485909129191}}</ref>
* Habermann's theory: The epithelium from the meatus or outer drum surface grows into the middle ear through a pre-existing perforation and form cholesteatoma.<ref name=Hab>{{cite journal |vauthors= Haberman J |title = Zur Entstehung des Cholesteatoms des Mittelohrs |journal = Archiv für Ohrenheilkunde |year = 1888 |pages = 43–51 |volume = 27 |issue = 2–3 |doi = 10.1007/BF02104525 |doi-access = free }}</ref>

Cholesteatoma may also arise as a result of [[metaplasia]] of the middle ear mucosa <ref>{{cite journal |author3-link=Geraldine Pinkus |vauthors = Sadé J, Babiacki A, Pinkus G |title = The metaplastic and congenital origin of cholesteatoma |journal = Acta Oto-Laryngologica |volume = 96 |issue = 1–2 |pages = 119–129 |year = 1983 |pmid = 6193677 |doi = 10.3109/00016488309132882 }}</ref> or implantation following trauma.