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This was a patient who had chronic otitis media.

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And there was a retro-tympanic white mass.

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So as soon as we hear a retro-tympanic white mass,

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we are concerned about a cholesteatoma.

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And often the clinicians will be able to look into

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the ear and see there is retraction of the tympanic

0:26

membrane, which might suggest a cholesteatoma.

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So in this case,

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we have the axial scans and we have the coronal

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scans. And as we scroll these images,

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you see a soft tissue mass,

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which is a little bit atypical in that it's not in

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that lateral process space with the scutum being

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eroded, but it's medial to the malleus and incus,

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and it does show mass effects.

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So as we look at the malleus here,

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we see that it's being displaced slightly laterally.

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And in addition,

1:01

there's some erosion of that malleus.

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It looks a little bit like a

1:06

blunted malleus as well.

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And we don't have the grape ice cream and ice cream

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cone of the head of the malleus and short process of

1:13

the incus. Here's our short process of the incus.

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Here's our malleus.

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Something's wrong here. And what's causing that?

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What's wrong is a cholesteatoma which is medial to

1:26

the middle ear, Oscar's. It's also, as you can see,

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expanding and eroding the anterior epitympanic recess.

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So the synonymous null of cholesteatoma is the presence

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of mass effect, the presence of erosion,

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the presence of dehiscence, and the MRI

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findings of restricted diffusion.

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So let's look at this on the coronal imaging.

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So, as I said,

1:52

the scutum looks good and the epitympanic space looks

1:55

good. And there's no erosion of the tegman tympani.

1:58

But we have this big soft tissue mass which is

2:01

pushing the malleus laterally and causing erosion

2:06

along the lateral surface of that malleus.

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Not only that,

2:10

but you see that the soft tissue is eroding the

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inferior wall of the facial nerve recess.

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So let's look at the facial nerve.

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Here we have the facial nerve.

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This is the descending portion of the facial nerve.

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This is the tympanic portion of the facial nerve.

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And as we follow it, we lose the wall,

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the bony wall of the facial nerve right here.

2:33

And there is soft tissue in the oval window around

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where we would expect the stapes to be.

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That is the cholesteatoma's extent.

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So going back to the axial scan,

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if here is the labyrinthine portion

2:49

of the facial nerve,

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here's the tympanic portion of the facial nerve,

2:53

and this wall here is eroded.

2:56

Here's the erosion of the wall.

2:58

Not only that, but we...

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Also see that the stapes has

3:03

soft tissue all around it.

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We see the little triangular shape of the stapes,

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but we can't really make out the incus because

3:09

there's cholesteatoma right in that space

3:13

between the incus and the stapes.

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So this is an example.

3:18

Again,

3:18

we also see the erosion of the attic

3:21

and the mastoid antrum.

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So this is an example of cholesteatoma leading to

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erosion of the ossicles, fusion of the malleus

3:30

head to the short process of the incus,

3:32

as well as dehiscence along the wall of the facial

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nerve. I just want to point out the cochlea here.

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So here we see the cochlea,

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which is far removed from the soft tissue,

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which is occurring in the oval window.

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Here is our cochlea over here.

3:56

Let's look at the MRI scan on this patient.

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We'll start with the CIS image.

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These are the thin section images.

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Again, slice location.

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We're going from 30.9 to 31.4.

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So we're at 0.5 millimeter.

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Thick sections again,

4:12

allows us to create multiplanar reconstructions.

4:15

You see the soft tissue infiltrating

4:18

and around the mastoid air cells.

4:21

But it does look like there's something different

4:24

between the soft tissue here,

4:28

anteriorly versus the soft tissue in

4:32

the mastoid and in the ad antrum.

4:35

So you want to be very careful looking at the

4:37

diffusion-weighted scan as to whether this is just

4:39

chronic otitis media with some erosion versus

4:43

cholesteatoma. So let's focus on this,

4:46

and let's get the diffusion-weighted scans up.

4:49

So in the diffusion-weighted images,

4:52

we do see something in here that's

4:54

a little bit bright on the DWI.

4:57

Not all that convincing, though.

5:00

Let's see whether the ADC maps help us.

5:04

So, again,

5:04

we're looking for something that's

5:06

darker in signal intensity,

5:07

identifying it as restricted diffusion

5:10

at the level of the pons.

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We got a little bit something dark right here.

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Most of this is bright.

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Let's give it a go with the post-contrast

5:19

enhanced scan.

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So non-enhancing tissue here corresponding to here.

5:25

This is the cochlea here,

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and this is that soft tissue just along

5:31

the lateral semicircular canal.

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And here is the lateral semicircular canal.

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So this tissue is not showing enhancement as

5:38

opposed to what's in the mastoid air cell.

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So although the diffusion-weighted scan was not all that

5:43

definitive, this did end up being a cholesteatoma.