Cholesteatoma - Theories and Pathogenesis

1. Theories &
Pathogenesis and
Overview of
Cholesteatoma
Tengku Ezulia
CME | ENT HRPZ II
25/8/2015

2. Definition
 (Abramson et al, 1977) Points to mention: [viva]
 3 dimensional epidermal and connective tissue
structure
 Forming a sac composed of a stratified squamous
epithelial outer lining and a desquamated keratin
center
 Conforming the middle ear cleft ( middle ear, attic,
mastoid)
 Capacity for progressive and independent growth
involving the underlying bone and replacing the
middle ear mucosa
 Tendency to recur

3. Classification
 Congenital
 Acquired
Primary
Secondary

4. Congenital Cholesteatoma
 Definition (Levenson, 1989) – 5 points
White mass medial to normal tympanic membrane
Normal pars flaccida and pars tensa
No prior history of otorrhea or perforations
No prior otologic procedures
Prior bouts of otitis media not grounds for exclusion

5. Theories “Congenital cholesteatoma”
 Epithelial cell rest theory
 Squamous metaplasia theory
 Epidermoid formation theory
 Invagination theory
 ESEI

6. Teed’s theory – Failure of involution of
embryonic cell rest
 Proposed in 1936
 The embryonic ectodermal epithelial cell rests
that is present during fetal development in
proximity to the geniculate ganglion fails to
involute.
 Persistence of embryonic squamous cell rests in the
temporal bone led to the formation of congenital
cholesteatoma.
 Presence of squamous cell rests in the temporal
bone – fairly common. Usually they involute at a
later date to become mature middle ear lining

7. Wendt’s Squamous Metaplastic theory
 This was first proposed by Wendt in 1873
 The attic area of the middle ear cavity is lined by
pavement epithelium.
 According to Wendt, this pavement epithelium
undergoes squamous metaplasia in response to
infection thus forming a nidus for cholesteatoma
formation.

8. Michael’s epidermoid formation theory
 Michaels in 1980s – fetal human temporal bones
 Identified squamous cell tuft present from 10-33 wk
of gestation.
 This “epidermoid formation” was noted in
anterosuperior wall of ME cleft.
 Failure of involution could be basis of cholesteatoma
in anterosuperior mesotympanum

9. Reudi’s invagination theory
 First proposed by Ruedi
 Suggested in-utero infection of TM causing it to
invaginate into the middle ear cavity and produce
stratified squamous epithelium.
 These invaginations predispose to cholesteatoma
formation.

10. Congenital Cholesteatoma
 Origin remains uncertain
 Usually starts from the antero superior quadrant
 Spreads through the posterior superior quadrant,
attic and finally into the mastoid cavity
 Mean age of presentation is 4.5 yo
 M:F ratio is 3:1
 Incidence is 0.12 per 100,000 people

11.  Anterosuperior quadrant > Posterosuperior quadrant

12. Acquired Cholesteatoma:
 subdivided into primary acquired and secondary acquired
cholesteatoma.

13. Primary Acquired Cholesteatoma
 Definition –
 Cholesteatomas that arise from retraction pockets
 Implies that infection has not given rise to the
cholesteatoma.

14. Pathogenesis
Invagination theory:
 Sterile OM → fibrosis and thickening of tympanic tissue→
attic block → localized negative pressure → localized
small retraction of pars flaccida
- Attic block and fibrosis also prevents normal
pneumatisation of epitympanum and mastoid
 Long standing Eustachian Tube Dysfunction
- Long standing OME or other eustachian tube disease →
ETD
- Negative middle ear pressure → retraction of pars
flaccida – Invagination (retraction pocket formation) →
accumulation of desquamated debris in the retraction
pocket → alteration to normal migration of
epithelium→accumulation of keratin

15. Primary Acquired Cholesteatomas
 Results in poor aeration of epitympanic space which
draws pars flaccida medially on top of malleus neck,
forming retraction pocket.
 Normal migratory pattern of the tympanic membrane
epithelium altered by retraction pocket
 Enhances potential accumulation of keratin

16. Primary Acquired Cholesteatomas
Pars flaccida retraction Pars tensa retraction

17. Secondary Acquired Cholesteatomas
Definition:
 Cholesteatomas that arise from a perforation in the
TM
– Implies a previous ear infection

18. Pathogenesis: SEPI
 Implantation theory
– Squamous epithelium implanted in the middle ear as a result of surgery
(iatrogenic), foreign body, blast injury etc.
 Squamous metaplasia theory
– Chronic otitis media / recurrent otitis media → desquamated epithelium
transformation to keratinized stratified squamous epithelium
 Epithelial migration theory
– Squamous epithelium migrates along perforation edge medially along
undersurface of tympanic membrane destroying the columnar epithelium.
– Secondary to ventilation tube / myringotomy insertion, tympanoplasty
 Papillary ingrowth / invasion theory
– Inflammatory reaction in Prussack’s space with an intact pars flaccida
causes break in basal membrane → marginal perforation → skin from EAC
wall migrates into the middle ear→ loss of contact inhibition with the middle
ear mucosa (destroyed by infection)
– Posterior superior TM

19. Common Sites of Acquired
Cholesteatoma Origin
 Posterior epitympanum
 Posterior mesotympanum
 Anterior epitympanum

20. Cholesteatoma Spread
Posterior epitympanic cholesteatoma passing through superior
incudal space and aditus antrum

21. Posterior mesotympanic cholesteatoma invading the sinus
tympani and facial recess

22. Anterior epitympanic cholesteatoma with extension to with
geniculate ganglion

23. Management
History:
1. Hearing loss
2. Otorrhea: malodorous
3. Otalgia
4. Tinnitus
5. Vertigo
Progressive unilateral hearing loss with a chronic foul smelling
otorrhea should raise suspicion.
 Previous history of middle ear disease
1. Chronic otitis media
2. Tympanic membrane perforation: Pars flaccida
3. Prior surgery

24. Examination:
 Otoscopy
 Microscopy
 Positive fistula (pneumatic otoscopy will result in
nystagmus and vertigo) response suggests erosion
of the semicircular canals or cochlea
 512Hz tuning fork exam
- Always relate with audiometry results

25. Hearing evaluation
 PTA: Conductive hearing loss
 Tympanometry
May suggest decreased compliance or TM
perforation

27.  Preoperative imaging with computed tomographies (CTs
) of temporal bones (2mm ) section without contrast in
axial and coronal planes.
1. Allows for evaluation of anatomy
2. May reveal evidence of the extent
3. Screen for asymptomatic complications
Imaging

28.  Treated surgically with primary goal of total eradication
of cholesteatoma to obtain a safe to and dry ear
1. Canal-wall -down procedures (CWD)
2. Canal-wall -up procedure (CWU)
3. Anterior atticotomy
4. Bondy’s procedure
Treatment

29.  CWD surgery approach procedure involves:
Taking down posterior canal wall to level of vertical facial
nerve
Exteriorizing the mastoid into external auditory canal

30.  Classic CWD operation is the modified radical
mastoidectomy in which middle ear space is
preserved
 Radical mastoidectomy is CWD operation in which:
Middle ear space is eliminated
Eustachian tube is plugged
 Meatoplasty should be large enough to allow good
aeration of mastoid cavity and permit easy
visualization to facilitate postoperative care and self
cleaning

31. Indications for CWD approach:
 Cholesteatoma in an only hearing ear
 Significant erosion of the posterior bony canal wall
 History of vertigo suggesting a labyrinthine fistula
 Recurrent cholesteatoma after canal-wall -up surgery
 Poor eustachian tube function
 Sclerotic mastoid with limited access to epitympanum

32.  Advantages:
 Residual disease is easily detected
 Recurrent disease is rare
 Facial recess is exteriorized
 Disadvantages:
 Open cavity created
Takes longer to heal
 Mastoid bowl maintenance can be a lifelong
problem
 Shallow middle ear space makes OCR (Ossicular
Chain Reconstruction) difficult
 Dry ear precautions are essential

33. Canal-Wall -Down

34. Bondy’s operation
 A type of modified radical mastoidectomy in which
the mastoid cavity is exteriorized without disturbing
the intact ossicular chain and pars tensa.
 Indication: epitympanic cholesteatoma with intact
ossicular chain, normal pars tensa, and good
hearing.
 The advantages of the technique are one-stage
surgery with preservation of preoperative hearing
levels, which is not possible with any other
procedure.

35. Canal -Wall -Up
 CWU procedure developed to avoid problems and
maintenance necessary with CWD procedures
 CWU consists of preservation of posterior bony
external auditory canal wall during simple
mastoidectomy with or without a posterior with
tympanotomy
 Staged procedure often necessary with a scheduled
second look operation at 6 to 18 months for:
- Removal of residual cholesteatoma
- Ossicular chain reconstruction if necessary
 Procedure should be adapted to extent of disease as
well as skill of otologist

36.  CWU indication:
-large pneumatized mastoid and well aerated middle
space
-Suggests good eustachian tube function
 CWU contraindicated in:
-Only hearing ear
Patients with labyrinthine fistula
-Long-standing ear disease
-Poor eustachian tube function

37. Canal-Wall -Up
 Advantages:
 Rapid healing time
 Easier long-term care
 Hearing aids easier to fit
 No water precautions
 Disadvantages:
 Technically more difficult
 Staged operation often necessary
 Recurrent disease possible
 Residual disease harder to detect

38. Canal-Wall -Up

39. Complications

40.  Hearing loss
 Facial nerve paresis or paralysis
 Labyrinthine fistula: semicircular canal erosion
 Extradural or perisinus abscess
 Serous or suppurative labyrinthitis
Extracranial complications

41. Intracranial Complications
 Potentially life-threatening
 Incidence: as high as 1%
 Complications
1. Periosteal abscess
2. Lateral sinus thrombosis
3. Intracranial abscess
4. Meningitis
 Symptom:
1. Suppurative malodorous otorrhea
2. Chronic headache
3. Fever
4. Otalgia

42. Take Home Message
 Theories /Pathogenesis of cholesteatoma remains
uncertain
 Basic knowledge of the important anatomic and
functional characteristics of the middle ear for successful
management of cholesteatomas
 Careful and thorough evaluations are the key to early
diagnosis and treatment
 Aim of treatment: eradicate disease and provide a safe
and dry ear
 Awareness of serious and potentially life-threatening
complications of cholesteatomas

43. Thank you so
much for your
kind attention

44. Reference:
1. Otology: an Overview By Prasad T Deshmukh,
Ansu Sam
2. Abramson et all. Cholesteatoma pathogenesis;
evidence of migration theory. Birmingham;
Aesculapius 1977. p176 -86
3. Imaging of the Temporal Bone By Joel D. Swartz,
Laurie A. Loevner
4. Ear, Nose and Throat Histopathology By Leslie
Michael