Chapter 41 - Cholesteatoma

Question 1

Two goals of cholesteatoma surgery

Answer 1

complete eradication (1)
preserve hearing (2)

Question 2

What is a cholesteatoma

Answer 2

epidermal inclusion cyst

squamous epithelium and debris

Question 3

Why are cholesteatomas destructive?

Answer 3

Surrounding inflammation

continually enlarge

Question 4

Why is it called cholesteatoma?

Answer 4

Light appearance, appeared like cholesteral cystals in microscopy, but now we know they actually DON’T have cholesteral or fat

Question 5

Congenital vs Primary acquired vs Secondary acquired

Answer 5

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

Question 6

Theories to explain origin of squamous debris in congenital cholesteatoma

Answer 6

epidermoid cell rests in middle ear (top theory)
squamous metaplasia
epithelial migration through TM microperfs
deposition of desquamated epithelial cells from amniotic fluid

Question 7

Theories to explain pathogenesis of acquired cholesteatomas

Answer 7

TM invagination (top theory for primary)
migration of epithelium through TM perforation
basal cell hyperplasia
squamous metaplasia 
implantation

Question 8

Explain invagination theory

Answer 8

TM retraction –> pocket with disrupted epithelial migration, drainage of keratin debris –> cholesteatoma

Question 9

What causes TM retraction

Answer 9

ETD, poor mastoid pneumatization, inflammation, TM atrophy

Question 10

How infections related to cholesteatoma differ from normal OM

Answer 10

polymicrobial

more anaerobes, antibiotic-resistant bacteria

Question 11

Why do cholesteatomas erode bone?

Answer 11

influx of inflammatory mediators
infection
both the above cause more bone resorption

Question 12

How do congenital cholesteatomas present?

Answer 12

white/yellow mass in anterior/superior quadrant
Intact TM, no otorrhea
Often ASx, but can have CHL, vertigo, CN VII, intracranial infxn

Question 13

How do acquired cholesteatomas present?

Answer 13

posterior superior retraction pocket at margin of TM with surrounding keratin debris
+/- perf, persistent foul-smelling otorrhea, granulation tissue

Question 14

Which image to order for cholesteatoma

Answer 14

CT

If suspect intracranial complication - MRI

Question 15

Common CT finding seen with acquired cholesteatoma

Answer 15

Blunting/erosion of scutum

Scutum is bony prominence in lateral middle ear and superior EAC

Question 16

Two possible complications of cholesteatoma around round window

Answer 16

SNHL, suppurative labyrinthitis

Question 17

Why use CN VII monitoring during cholesteatoma surgery

Answer 17

Improves identification of dehiscence
Decreased rate of CN VII injury (small)
Especially use for revision surgery or extensive disease

Question 18

Risks of cholesteatoma surgery

Answer 18

Incomplete disease reoval, hearing loss, vertigo, encephalocele, bleeding, need for second look, facial nerve injury, CSF leak, change/alteration in taste, infection

Question 19

What can cause vertigo after CWD mastoidectomy?

Answer 19

temperature changes with air/water exposure

Question 20

When to perform ossiculoplasty after CWU mastoidectomy

Answer 20

At second look, if free of dz

Question 21

When to do second look adults vs kids

Answer 21

6-9 mo for kids (more likely to recur)

9-12 mo for adults

Question 22

What is a mastoid cavity obliteration?

Answer 22

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

Question 23

Can you image rather than do second look?

Answer 23

Yes.

Non-echo-planar-based diffusion-weighted MRI has high reliability to detect cholesteatoma recurrence