Chapter 41 - Cholesteatoma Flashcards
Two goals of cholesteatoma surgery
complete eradication (1) preserve hearing (2)
What is a cholesteatoma
epidermal inclusion cyst
squamous epithelium and debris
Why are cholesteatomas destructive?
Surrounding inflammation
continually enlarge
Why is it called cholesteatoma?
Light appearance, appeared like cholesteral cystals in microscopy, but now we know they actually DON’T have cholesteral or fat
Congenital vs Primary acquired vs Secondary acquired
Congenital: originate from keratinizing squamous epithelium of middle ear cleft
Primary: TM retraction (ETD, otitis media), usually pars flaccida, but can develop in pars tensa
Secondary: TM perf
Theories to explain origin of squamous debris in congenital cholesteatoma
epidermoid cell rests in middle ear (top theory)
squamous metaplasia
epithelial migration through TM microperfs
deposition of desquamated epithelial cells from amniotic fluid
Theories to explain pathogenesis of acquired cholesteatomas
TM invagination (top theory for primary) migration of epithelium through TM perforation basal cell hyperplasia squamous metaplasia implantation
Explain invagination theory
TM retraction –> pocket with disrupted epithelial migration, drainage of keratin debris –> cholesteatoma
What causes TM retraction
ETD, poor mastoid pneumatization, inflammation, TM atrophy
How infections related to cholesteatoma differ from normal OM
polymicrobial
more anaerobes, antibiotic-resistant bacteria
Why do cholesteatomas erode bone?
influx of inflammatory mediators
infection
both the above cause more bone resorption
How do congenital cholesteatomas present?
white/yellow mass in anterior/superior quadrant
Intact TM, no otorrhea
Often ASx, but can have CHL, vertigo, CN VII, intracranial infxn
How do acquired cholesteatomas present?
posterior superior retraction pocket at margin of TM with surrounding keratin debris
+/- perf, persistent foul-smelling otorrhea, granulation tissue
Which image to order for cholesteatoma
CT
If suspect intracranial complication - MRI
Common CT finding seen with acquired cholesteatoma
Blunting/erosion of scutum
Scutum is bony prominence in lateral middle ear and superior EAC
Two possible complications of cholesteatoma around round window
SNHL, suppurative labyrinthitis
Why use CN VII monitoring during cholesteatoma surgery
Improves identification of dehiscence
Decreased rate of CN VII injury (small)
Especially use for revision surgery or extensive disease
Risks of cholesteatoma surgery
Incomplete disease reoval, hearing loss, vertigo, encephalocele, bleeding, need for second look, facial nerve injury, CSF leak, change/alteration in taste, infection
What can cause vertigo after CWD mastoidectomy?
temperature changes with air/water exposure
When to perform ossiculoplasty after CWU mastoidectomy
At second look, if free of dz
When to do second look adults vs kids
6-9 mo for kids (more likely to recur)
9-12 mo for adults
What is a mastoid cavity obliteration?
Performed as part of a CWD procedure where you reconstruct the posterior wall at the end, and then fill mastoid with inert material
This keeps you from having to keep patient on frequent cleaning/water restriction, and allows better hearing aid function, while giving you the exposure of a CWD
Can you image rather than do second look?
Yes.
Non-echo-planar-based diffusion-weighted MRI has high reliability to detect cholesteatoma recurrence
