0:01

So here we have a patient, a 75-year-old

0:03

gentleman, who came from an outside

0:05

institution, didn’t have a lot of history

0:07

on this one. History is abdominal

0:09

pain and no real prior studies, and so

0:11

we're asked to look at this patient.

0:15

And so this was performed as a two

0:18

phase study, pancreatic mass protocol.

0:21

And so we’re going to look at the pancreatic

0:23

phase, which is a relatively arterial phase

0:25

study done with pancreatic parenchyma.

0:28

is enhancing at its optimum amount.

0:31

And so you can already see here that

0:34

the bile duct is dilated over here.

0:36

It’s not largely dilated, but the fact

0:38

that you see it tells us that there

0:40

is some mild intrahepatic ductal

0:42

dilatation, at least on that slice.

0:44

As we go downwards, we can start to see that

0:46

there are more bile ducts that are dilated,

0:47

particularly in the right hepatic lobe, maybe

0:49

a little bit in the left hepatic lobe as well.

0:53

The more you look, the more you see

0:54

dilated bile ducts, dilated bile ducts.

0:56

Here, this looks a little bit dilated as well.

1:01

I want you to notice that the extrahepatic biliary

1:03

tree looks a little bit different than some of

1:06

the cases we’ve seen in that there is marked

1:09

enhancement and thickening of its wall, right?

1:12

We’ve seen dilated bile ducts.

1:14

We haven’t quite seen this degree

1:15

of thickening involving the wall

1:17

and that degree of enhancement.

1:19

And it’s quite focal right over here,

1:20

because as you scroll downwards, it

1:22

just doesn’t look as bad anymore.

1:25

And so let’s zoom out again for

1:27

a second, and I’m just going to scroll

1:30

in and out of here just to get you

1:31

a global picture of what’s going on.

1:33

Certain areas of intrahepatic ductal

1:36

dilatation, the extrahepatic biliary

1:38

tree is quite thick, quite enhancing.

1:40

And so there’s certainly something

1:42

going on with this person’s bile ducts.

1:45

And, you know, if you were to look at this

1:47

and sort of describe it as, you know, signs

1:49

of intrahepatic ductal

1:51

dilatation associated with signs of relative

1:54

narrowing of the intrahepatic bile ducts and,

1:57

you know, multifocal in its distribution.

1:59

Now, you’d probably be describing

2:01

something that can be attributed to

2:03

primary sclerosing cholangitis in this

2:05

instance, also affecting the extrahepatic

2:08

dilatation areas of ductal dilatation.

2:11

However, there’s a little bit more

2:12

going on in this case than just that.

2:13

So the other thing I’ll focus

2:15

on next is the pancreas itself.

2:18

And if you look at the pancreas, it also

2:20

has this, uh, sort of abnormal appearance.

2:23

And there are two portions

2:24

of it that look abnormal.

2:26

The body over here and tail look very abnormal.

2:29

You can compare it to the pancreatic parenchyma

2:32

over the, uh, body and neck region,

2:35

which is enhancing relatively

2:36

normally, nice and bright here.

2:38

It's not enhancing nice and bright.

2:40

It's much darker in its enhancement.

2:42

Okay.

2:42

And it almost looks more mass-like, and that

2:44

it's just sort of expanded a little bit.

2:46

And then in the head of the pancreas

2:48

looks quite similar as well, and that

2:49

it looks darker than we would expect.

2:51

It looks a little bit expanded.

2:53

The duct that we see, you know, in

2:55

between those two areas does look dilated.

2:59

And so you would not be mistaken for thinking

3:02

that, you know, particularly given that the head

3:04

of the pancreas looks a little bit enlarged and

3:06

that the duct upstream from it is dilated, that

3:08

we're dealing with potentially a pancreatic

3:10

neoplasm resulting in ductal dilatation.

3:13

However, it'd be unusual for there

3:15

to be sort of multifocal cancers, i.e.

3:17

90 00:03:17,670 --> 00:03:19,180 one in the head of the pancreas,

3:19

and then one involving the body and tail.

3:21

And if we also notice very carefully within

3:23

the tail of the pancreas, there is a portion

3:26

of the duct that actually is normal caliber.

3:28

So in fact, if you think about it,

3:30

if this indeed was all tumor, we

3:33

really shouldn't be seeing a normal duct

3:35

that's sort of coursing through it.

3:36

It looks relatively normal in its appearance.

3:39

And so that I think would make it

3:41

unusual for this, at least the tail

3:43

of the pancreas to be all a tumor.

3:45

And so one other explanation that could sort

3:48

of put everything together because the findings

3:50

of tumor would then also not explain the

3:52

findings in the intrahepatic bile ducts or the

3:54

extrahepatic biliary tree, which is thickened,

3:56

is this idea that in fact, the findings

3:59

in the pancreas reflect something called

4:01

autoimmune pancreatitis, where you get

4:04

regions of thickening of the pancreas

4:07

that is often diffuse, but it can also be

4:09

focal, and in this instance, multifocal.

4:12

And it's a form of pancreatitis which

4:15

is associated with this bigger sort

4:18

of syndrome of IgG4-related diseases,

4:21

which is thought to be immune-mediated.

4:24

And I think one of the clues that can

4:26

sort of clue you into that is the fact

4:27

that some of the ducts that are coursing

4:30

through the area of abnormal parenchyma

4:33

actually look relatively normal.

4:35

Now IgG4-related disease can affect a

4:38

whole bunch of organs in the abdomen and

4:41

pelvis and indeed elsewhere in the body,

4:44

but it can also affect the bile ducts and

4:46

cause areas of multifocal stricturing.

4:49

And you get an appearance that's quite similar

4:51

to this in the sense that you get areas

4:52

of bile duct thickening and enhancement.

4:56

Upstream from these areas of

4:58

thickening and enhancement, you'll

4:59

see areas that are relatively dilated.

5:02

And so, you know, I think this is an

5:04

instance where you just sort of have

5:06

to put the whole picture together.

5:09

Up with a diagnosis that this is all

5:11

related to IgG4-related disease.

5:13

And in fact, this was the case in this instance

5:16

where this person had IgG4-related disease

5:19

and one of the significances of knowing that

5:22

is that these patients often respond well

5:24

to steroids, and so if you're able to sort

5:27

of suggest that to your referring providers

5:30

prospectively, they can test for IgG4-related

5:33

disease by doing some lab values, and if

5:35

positive, they can then treat with steroids.

5:38

This is just showing you the same findings

5:39

on the coronal plane, showing you that

5:41

thickening of the, uh, biliary tree, associated

5:45

with areas of focal ductal dilatation upstream

5:49

from regions of multifocal stricturing.

5:52

A nice case of IgG4-related disease affecting

5:55

the pancreas as well as the bile ducts.