0:01

Another mass-like abnormality that

0:03

we might come across is the presence

0:05

of peritoneal inclusion cysts.

0:08

So this is non-malignant proliferation

0:10

of peritoneal cells, and it's a

0:12

response that's reactive to peritoneal

0:14

irritation and the presence of adhesions.

0:17

So who forms adhesions?

0:19

It's patients who have had prior

0:21

surgery or inflammation in the pelvis.

0:23

So patients with endometriosis, PID,

0:27

patients with ulcerative colitis

0:29

that have had surgeries before.

0:30

So really anybody who's had some

0:32

sort of irritation or surgery that

0:34

could cause adhesions is at risk of

0:37

developing a peritoneal inclusion cyst.

0:39

So what is this exactly?

0:41

Well, this diagram shows a very large

0:44

mass that's composed of lots of different

0:46

cystic locules with intervening septations.

0:49

And somewhere in there is an ovary.

0:52

So it's hard to know, is it this

0:53

structure here or over here?

0:55

But the hallmark of a peritoneal inclusion

0:57

cyst is the fact that the ovary gets trapped

1:01

between all of these different adhesions.

1:03

And the reason that there are adhesions

1:06

with fluid is that the ovary is secreting

1:10

fluid that kind of gets trapped.

1:11

Normally, it would get swept through the

1:13

normal flow of fluid within the peritoneal

1:16

cavity, but in a patient with adhesions,

1:18

the fluid may not have a good exit route.

1:21

So it gets trapped.

1:23

in these adhesions and eventually

1:25

sealed off, and that's what creates

1:27

this peritoneal inclusion cyst.

1:29

So because the ovary is secreting fluid, that

1:31

implies that it's really only patients who

1:34

have functioning ovaries or are premenopausal

1:37

that develop peritoneal inclusion cysts,

1:40

and it's commonly described as a spider-web

1:42

appearance with the ovary trapped in the middle.

1:46

Okay, so here's a patient that I wanted to

1:49

show you who actually had ultrasound and MRI.

1:54

So I'll just show you both sets of images here.

1:58

So here we've got a sagittal image

2:00

of the left adnexa on the top and

2:04

then transverse on the top right.

2:11

So you can see that there's a cystic

2:15

structure that looks a little bit complex.

2:18

It's not just a simple cyst.

2:20

It's got multiple components and then

2:23

it's got one locule that looks like it

2:26

has some material in it, maybe hemorrhage.

2:30

It just looks like, you know, what you might

2:33

imagine a hemorrhagic cyst would look like.

2:35

So that's here.

2:37

No nodular components that we can see, but

2:40

there's definitely a septation and we don't

2:42

really see a normal ovary on the left side.

2:45

So let's take a look at the right side now.

2:48

So this is the right adnexa.

2:50

Here's the uterus.

2:52

You can see back here that there's some bowel,

2:56

and we can see in the right adnexa,

3:00

there's a similar-looking structure, maybe

3:02

a little bit more simple, but pretty big.

3:06

Definitely at least one locule, maybe

3:08

two, and maybe a little tubular component

3:13

right back here, but again, we don't see

3:17

a normal ovary on the right side either.

3:21

So I'm just going to pause all of those.

3:25

So, it's hard to tell on the ultrasound

3:27

exactly what we're dealing with, but

3:28

we've got bilateral cystic structures,

3:31

and this is a reproductive-age woman.

3:33

One of the structures on the left looks

3:35

like it might have a hemorrhagic component.

3:38

So maybe is this a hemorrhagic

3:40

cyst, but it looks a bit unusual.

3:43

So we recommended that this patient

3:45

undergo MRI, so we weren't really sure

3:48

what this cystic structure was.

3:52

Okay, so here's the MRI so you can see that the

3:55

cystic structures are quite large, particularly

3:57

on the right, and you get the impression

4:00

from the ultrasound on the right that maybe

4:01

we're not seeing the whole picture, so that

4:04

in itself is a good indication to do MRI just

4:07

to make sure we're covering the whole cyst.

4:09

So notice that we start imaging just

4:12

above the aortic bifurcation where the

4:14

IMA comes off, just to make sure we're

4:16

covering everything, and then we get a look

4:19

at this multicystic right ovarian cyst.

4:23

The septations are quite thin.

4:25

There's no internal nodules that we can see.

4:30

And then a similar appearance on the left.

4:34

This might account for that

4:35

cystic structure on the left.

4:37

There's a little bit of a

4:38

difference in the T2 signal here.

4:42

So let me see if I can just put up

4:45

here's the T1-weighted images here.

4:48

And everything looks pretty simple.

4:50

So there's no hemorrhage, and

4:52

there's no fat within these.

4:53

So we know we're dealing with simple fluid.

4:55

So now the key is, okay, we need to know,

4:59

first of all, are there normal ovaries?

5:02

And then we need to know,

5:03

what's the patient's history.

5:04

So I'm looking for normal

5:07

ovaries on the right, because we

5:11

didn't see that on the ultrasound.

5:14

And the only bit of ovarian tissue

5:17

I think I can see is right here.

5:20

So hopefully you can see that as well.

5:22

And the reason I think this is ovarian tissue

5:24

is because I can see tiny little follicles.

5:27

So to me, it looks like these tiny little

5:29

follicles have been squished by this multicystic

5:33

structure that's sort of entrapping the

5:35

ovary and that's sort of that spider web pattern

5:38

that you'd see in a peritoneal inclusion cyst.

5:41

And again on the left side, maybe we can

5:43

see a bit of ovarian tissue that's smooth

5:46

and flat with maybe a bit of a couple of

5:48

little follicles there, but again, it looks

5:51

like the ovaries are just being squished by

5:53

the mass effect from these bilateral cystic

5:55

structures, which contain simple fluid.

5:58

So now we're thinking maybe

6:00

peritoneal inclusion cysts.

6:02

What really cinches the diagnosis in this case

6:05

is that this patient has IBD and has

6:09

a J pouch, and you can see that the

6:11

wall of the J pouch looks thickened.

6:14

So there's some submucosal high T2 signal.

6:17

Let's just check.

6:18

Is that fat or is that edema?

6:20

It's going to be a little bit hard to tell.

6:23

On the T1 Fatsat.

6:24

So I'm going to just put up the

6:27

inversion recovery in this case.

6:29

And it looks like we've got some high

6:31

T2 signal there in the submucosa.

6:33

So this looks like it's probably edema.

6:36

And you notice that there's some prominence of

6:39

the vasa recta extending towards the J pouch.

6:43

And then we also have some pretty

6:45

large high T2 signal nodes here.

6:48

So this is pretty diagnostic

6:50

of pouchitis in this patient.

6:53

So that history combined with the findings

6:55

on ultrasound and MRI leads us to be pretty

6:58

confident that what we're dealing with here

7:00

are bilateral peritoneal inclusion cysts.