0:00

So I have one more case and this one is going to be

0:03

a show and tell. And this is also two patients and then we'll

0:07

be able to answer some questions if there are any.

0:10

This case just is more of a detection case.

0:18

You can see that there's definitely a rectal cancer here, so it's a

0:25

mid to high rectal cancer. And you can see that it looks like

0:28

there is some extension already on the sagittal,

0:32

deep to the muscular. And then we've got this suspicious little

0:37

extension here. And we talked about the anterior peritoneal reflection in

0:43

one of our other cases. Again, let's outline that here. Here it is.

0:47

And again, in males, the reflection is at the level of the seminal

0:51

vesicle. But what we sometimes don't think about is that the anterior peritoneal

0:56

reflection also extends laterally. In this case, you can see the lateral

1:02

margin of the anterior peritoneal reflection on the left, and it is involved

1:06

by tumor. We might get lulled into the habit of looking at the

1:10

anterior peritoneal reflection on the sagittal images because that's usually

1:13

how we identify it. But don't forget that it does extend laterally.

1:18

And so, if you see this, this is automatically a T4a lesion. So

1:24

we've got involvement of the anterior peritoneal reflection as it extends

1:27

laterally. So this is by definition T4a already at least.

1:32

And now we're going to see, okay, does this extend to involve any

1:35

of the solid organs or the ureter or

1:39

the seminal vesicles, etcetera? And that would upstage it to T4b. But in

1:45

this case, this was a T4a. So you can see that the

1:49

bladder also has a lot of little diverticula and then we've got a

1:53

male patient here, so we're going to scroll through the prostate glands,

1:58

and I'm just going to load up the diffusion here.

2:07

Okay. So I don't know how many of you do prostate imaging,

2:13

but it's not uncommon to see something like this.

2:22

In the left posterior peripheral zone, we've got

2:26

pretty large wedge shaped to roundish area of low T2 signal.

2:34

And there's corresponding reduced signal on the ADC map.

2:39

Let's see what happens on diffusion. So, that's light bulb bright on high

2:43

b value diffusion. So this patient not only unfortunately has T4a disease

2:50

with involvement of the anterior peritoneal reflection from the rectal cancer,

2:54

but has a concomitant prostate cancer. So, very bad luck for this patient.

2:59

So, teaching point here is to not fall victim to the satisfaction of

3:06

search. So, look at all of the organs in the pelvis. And the

3:10

other teaching point was about the anterior peritoneal reflection and the

3:13

anatomy there. You can see also this patient,

3:17

I think, had a few little areas that looked concerning for tumor deposits

3:23

or lymph nodes. Unfortunately, a lot going on in this patient.

3:29

There's another one here. That was just a little show and tell.

3:33

And then I have another patient that had some interesting findings as well.

3:37

This is a fairly new case that I had.

3:42

So, this patient was scoped and there was a pretty significant abnormality,

3:49

which is hard to miss on this case. So

3:53

this is a really, again, a really nice example of what rectal cancers

3:56

or what cancers in the colon look like.

4:00

Again, raised rolled edges. And then there's the little ulcer, the central

4:04

depression, and then the other raised rolled edge. But this does not look

4:08

like your typical rectal cancer because there's all this abnormal low T2

4:13

signal in the wall, so deep to the mucosa... This is all sub mucosal involvement

4:19

here of whatever this is. And then it forms this triangular shape.

4:26

You have all this low T2 signal also involving the anterior peritoneal reflection

4:31

and the base of the prostate gland posteriorly. So,

4:36

this is another example. Take a look at this. Look at this anterior peritoneal

4:40

reflection again, laterally and anteriorly. Very abnormal thickened low

4:46

T2 signal. And this is one of the most dramatic

4:51

images of anterior peritoneal reflection anatomy that I've seen. So, diffusely

4:56

thickened, extending anteriorly. You can start to see a bit of ascites in

5:01

the pelvis. Look how thick that is. So

5:05

the question here was, is this a primary rectal cancer invading the prostate

5:10

or is it going backwards involving the prostate and then involving the rectum?

5:15

So, the thought was, because there's an ulcer in the mucosa here,

5:18

it's probably rectal in origin and then extending to involve the anterior

5:23

peritoneal reflection and the prostate either by a vascular or lymphatic

5:28

channel. But we weren't completely sure, so we asked for a PSA correlation,

5:33

etcetera, and the PSA was normal, but the CEA was sky high.

5:39

And so for this case, I also have...

5:43

Hopefully you can see that, yeah. So I have some really interesting endoscopic

5:47

and histologic findings here. So, these were the endoscopic images. Remember

5:52

I showed you the tumor itself with the raised rolled edge and then the

5:55

central ulcer. So, that's that ulcer here. So, very hemorrhagic looking

6:00

lesion with lots of telangiectasia, very thickened. And then at biopsy,

6:06

so the patient actually had two biopsies, there was infiltration of tumor

6:14

into the submucosa. So the mucosa itself was ulcerated, but the reason this

6:19

was so thickened and the reason we had all of that low T2

6:22

signal in the submucosa on the MR was because there was massive lamina propria

6:30

and submucosa infiltration of that tumor. So, this was a primary rectal

6:34

cancer, but notice how... See, these are the glands here that are relatively

6:38

preserved. There was only one area, only that ulcerated area, and here you

6:43

see the red blood cells. Only that ulcerated area had mucosal involvement.

6:47

So the rest of the mucosal glands are preserved and then you've got

6:51

this infiltration of tumor in the submucosa. So, this is

6:55

a really neat case, not for the patient, but for us to learn

6:58

from, because it's a very unusual pattern of

7:04

spread of rectal cancer. So, that was just my show and tell for

7:08

the day. So, hopefully you learned something about the peritoneal reflection

7:13

on those last two cases.