Review of IgG4-related Disease in the Abdomen and Pelvis, Dr. Mahan Mathur (5-7-25)
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Today we are honored to welcome Dr.
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Mahan Mather for a lecture entitled Review of
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IgG four Related Disease in the Abdomen and Pelvis.
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Since 2013, Dr.
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Mather has served as the faculty at the Yale School
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of Medicine, where he's an associate professor of radiology
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and biomedical imaging and vice chair of education.
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Dr. Mather is passionate about radiology education
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and mentorship and has been the recipient
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of the RSNA Honored Educator Award in 2017
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and 2021, as well as numerous departmental teacher
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and mentor of the year awards.
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At the end of the lecture, please join Dr.
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Mather in a q and a session
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where he will address questions you
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may have on today's topic.
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Please remember to use the q
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and a feature to submit your questions so we can get to
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as many as we can before our time is up.
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With that, we are ready to begin today's lecture. Dr.
1:09
Mather, please take it from here.
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Warm welcome to everybody.
1:13
And for those who were maybe taken aback by
1:16
LGG four related disease,
1:18
we are not talking about lgg related four disease.
1:20
We're talking about IgG four related disease of the abdomen
1:24
and pelvis, but I can see how that eye can look like an,
1:26
uh, an L over there.
1:28
So, um, we're gonna be talking about this for the next hour
1:30
or so, and I'm so honored and glad to be here.
1:33
Um, it's been a while since I've been on this stage
1:35
and uh, it's always a pleasure to be back
1:38
and I see a lot of people in the audience.
1:39
This is gonna be a lot of fun for me. Thank you.
1:41
So we have some objectives for this session,
1:45
me talking about the pathophysiology
1:47
of IgG four related disease,
1:50
and at the end of this you'll have some idea
1:52
what happens, why this occurs.
1:54
Uh, we're gonna spend most
1:55
of the time talking about the abdominal
1:58
and pelvic imaging manifestations of this.
2:00
So this is a disease that can affect any body part,
2:03
but I'm an abdominal radiologist,
2:04
so my focus is really on abdominal and pelvic imaging.
2:07
And we're also in the midst of looking
2:11
through different organ systems.
2:12
We're gonna talk about some disease mimics
2:14
and do some comparing
2:15
and contrasting of how these disease mimics can look similar
2:19
and how yet they're different from IgG four related disease.
2:22
I have some disclosures, none are relevant
2:24
to this specific presentation.
2:28
So let's define what this entity is
2:31
and we'll use that as a launching pad to go deep
2:35
and talk a little bit more specifically about it.
2:37
So, IgG four related disease,
2:39
it's an immune-mediated disease
2:41
and it's exemplified by chronic inflammation.
2:44
That chronic inflammation results in fibrosis,
2:47
and that fibrosis involves
2:50
multiple organs throughout the body.
2:52
Alright, so there's some key sort of terms within
2:55
that definition that I'm gonna sort
2:56
of expand on a little bit.
2:58
First is the word immune mediated.
3:01
All right, so let's talk about the immune mediation
3:04
of IgG four related disease.
3:06
Now we're not really sure why this disease occurs,
3:09
but what we think in our current understanding is
3:12
that it is triggered by an auto antigen.
3:16
We're not sure why it is, we're not sure why the body starts
3:19
to react that way to one of those antigens,
3:22
but that's what happens.
3:24
There's an immunological response that's triggered
3:27
by an exposure to an auto antigen at some point, uh,
3:31
in our patient's life.
3:32
This then elicits a response on the cellular level
3:37
that's t uh, uh, exemplified by, um, an accumulation
3:42
of helper and regulatory T cells that then start
3:45
to secrete these cytokines.
3:47
Now it's these cytokines that allow proliferation
3:50
of multiple other cell types, the eosinophils, the B cells,
3:53
plasma cells, fibroblasts throughout the body.
3:56
Those that end up clumping together, for lack
3:59
of a better word to form this very discreet
4:04
lymphoplasmacytic infiltrate.
4:06
And it is that infiltrate that then goes ahead
4:09
and deposits on the cellular membranes resulting in
4:13
fibrosis and over a period
4:15
of time resulting in cellular damage.
4:21
So that's the immune-mediated response.
4:23
There's an auto antigen, the body reacts to it
4:25
and can cause all this inflammation and fibrosis.
4:29
So let's dive deeper into the inflammation
4:31
and fibrosis portion of this illness.
4:36
And so as mentioned, there's these dense
4:39
lymphoplasmacytic infiltrates,
4:41
and when you do end up biopsying
4:43
and you do have to biopsy tissue in order
4:45
to facilitate a diagnosis of IgG four related disease,
4:48
what you will find under the microscope is a variable degree
4:52
of fibrosis.
4:53
And there is a very characteristic story form pattern that,
4:57
uh, the pathologist can see.
4:59
I'm not a pathologist and so take my word for it.
5:01
It's supposed to look like woven fabric.
5:04
And so this is sort of the dense lymph plasmatic infiltrates
5:07
with fibrosis.
5:08
These are that in
5:09
that story form pattern is supposedly looks
5:12
like a woven fabric.
5:13
Um, you know, uh,
5:15
embedding all these lymphoplasmacytic infiltrates
5:18
and there are stains that can be applied, um,
5:21
on these, uh, slides.
5:23
And there are criteria that the pathologists use to suggest
5:26
that there's IgG four related disease, whether there's
5:29
a percentage of IgG four related disease
5:31
amongst all the IG plasma cells that are seen
5:33
or how many they see in a specific specimen.
5:36
We don't need to get to move too much detail,
5:38
but there are states and there are criteria
5:39
that they use in order to make that diagnosis.
5:42
And there's also an deliberative, uh, uh,
5:45
uh, let me just see.
5:47
Okay, just wanna make sure there was a comment there.
5:49
But I think we're dealing with that in the, uh, in the chat.
5:51
There's also an obliterated, a phlebitis
5:54
that's characteristic where the vessels sort of, uh,
5:56
become inflamed and obliterated.
5:58
Apparently that's characteristic
6:00
of IGG four related disease.
6:04
And there are serum values that, uh,
6:07
one can look for as well.
6:08
And generally the serum antibodies
6:10
of IgG four are elevated in this
6:12
disease, as you would expect.
6:15
Um, but it's not elevated in everybody, only up
6:17
to about 70% of patients.
6:19
And it's thought now
6:20
that it's not necessarily pathic mnemonic of this disease,
6:24
but that the IgG four antibodies are elevated rather
6:27
as part of the immune response.
6:28
And that perhaps there's some other diseases out there
6:31
that can have a similar pathophysiology
6:34
but are different disease entities
6:36
that perhaps can also result in an abundance
6:38
of IgG four related serum antibodies.
6:41
So the bottom line though is that listen,
6:43
there are pathologic features you can see when you do the
6:47
biopsy and you have to do biopsy to make that diagnosis.
6:49
But it really is a multidisciplinary effort.
6:52
There's a clinical picture that we'll talk about of patients
6:55
who come in with perhaps IgG four a disease.
6:57
There's certain histologic
6:58
and serological findings that you have to look for,
7:00
but just as important, there's radiological data
7:03
and that's really where we come in
7:04
and perhaps the radiologists are, uh, uh, one of the first
7:07
to detect signs of this disease
7:09
and the imaging manifestations of it
7:11
that can then inform our colleagues
7:13
that this is what's going on
7:14
and everything will then fit into that puzzle of
7:16
what the patient's going through.
7:19
So immune mediated causing inflammation resulting in
7:22
fibrosis and involving organs.
7:24
So let's talk a little bit about the organs.
7:26
This is just a schematic taken from the literature showing
7:29
all the organs that have been reportedly, uh, affected
7:32
by IgG four related disease.
7:34
So anywhere from the head
7:35
and neck region, things like orbital tumor, tumor,
7:37
things involving the trachea, interstitial,
7:39
some different types of interstitial
7:41
pneumonitis as well in the lungs.
7:42
But of course all of these diseases here in the
7:44
abdomen and pelvis.
7:46
And I think what's interesting here is that so many
7:48
of these diseases are considered separate entities.
7:52
Um, but what we're finding is that perhaps many of them
7:56
fit nicely under the umbrella of I HG four related disease.
7:59
And so increasingly as people are doing research on this
8:02
and people are getting more information about this,
8:04
perhaps we are going to reclassify some of the diseases
8:08
that we thought were distinct entities as nothing
8:11
but a manifestation of IEG four related disease
8:17
and multiple organs are often involved when the patients
8:21
present clinically and up to 60 to 90% of patients.
8:24
And what that means from a radiologist's perspective,
8:27
that if you see a sign
8:28
of IG four related disease in one organ look elsewhere,
8:32
and you know there's a good chance you're gonna find
8:35
elements of IG four related disease in other organs.
8:37
Now within the abdomen pelvis, the three places
8:39
that I think are the most high yield to look,
8:41
and we'll talk a lot about these in the next coming upcoming
8:43
slides of the pancreas, the biliary system,
8:46
and the retroperitoneum.
8:48
Alright, so those are the three places that I look for.
8:50
I also look at other places that I'll talk about,
8:52
but those are the three top three places that my eyes go
8:55
to once I think that there's some element
8:57
of IgG four related disease brewing, uh, within the body.
9:01
Now, from a clinical perspective, it is challenging
9:03
for our providers
9:04
because, uh, it's quite an insidious disease onset.
9:07
There's generally no fever or rapid organ failure.
9:10
It's people who have sort of low level symptoms
9:13
for a long period of time
9:14
that then come to clinical attention.
9:16
Now, when they come to clinical attention, about 60%
9:19
of them may have irreversible organ damage.
9:21
So, you know, we wanna catch them earlier when perhaps
9:24
they're just feeling fatigued
9:25
or have a little bit of weight loss or something's going on.
9:27
And that's where the radiologist again comes in.
9:29
And maybe we can make that finding early enough
9:31
before we get to the organ dysfunction phase.
9:34
Um, and so, uh, it is challenging
9:36
that is from the clinical perspective to detect this.
9:39
And the reason of course,
9:41
that it becomes an important disease to be able
9:43
to detect from a radiology perspective is
9:45
that we have effective treatment.
9:46
If there was no effective treatment, then again,
9:48
it would just be us detecting something
9:50
for which we couldn't do much about.
9:52
But it turns out that if you detect this disease,
9:54
if you diagnose this disease
9:56
and you start patients on steroids,
9:58
they will often get better.
10:00
Now there's, they taper the steroids, a discontinuation,
10:03
they follow up clinically to make sure they're doing better.
10:05
They follow up their serum levels,
10:06
they follow up any laboratory parameters
10:09
to suggest organ function getting improved.
10:12
And the imaging findings, well,
10:13
they make sure those imaging findings
10:14
get better over a period of time.
10:15
So you'll see follow-up imaging on patients
10:17
who you've diagnosed IgG four related disease,
10:20
and, um, it'll be so, you know, often nice to see
10:22
that you've suggested the disease,
10:24
they've confirmed the disease, they've started to steroids.
10:27
Now you see the imaging again,
10:28
and all of a sudden they're better.
10:29
It's quite gratifying.
10:31
Now if steroids, uh, don't work
10:33
or if there's a contraindication to steroids, there is, uh,
10:36
rituximab or a monoclonal antibody that can be used,
10:39
uh, as a second line therapy.
10:40
And the third bullet point I put here is that, you know,
10:43
oftentimes you'll need some sort
10:45
of interventional radiology,
10:46
potentially surgical procedure also in the mix.
10:49
For example, if it's affecting the biliary tree,
10:51
you may need to have biliary drainage.
10:53
If it's affecting other organs, you may need
10:54
to drain those organs effectively until the steroids kick in
10:57
and, uh, and result in the appropriate treatment.
11:03
So why am I talking about this, right?
11:06
Is this, uh, do we have, uh, a preponderance
11:08
of disease out there of IG four disease?
11:10
Is it that important that we need to dedicate an hour to it?
11:13
Well, there's very limited data.
11:15
Um, so we don't really know.
11:17
Um, I would say anecdotally,
11:19
and if you look at the literature, there's really an
11:21
increased recognition
11:22
of this disease entity in the last couple of years.
11:26
Uh, there's a lot of being published about this.
11:28
Um, and you know, one of the issues that comes up with sort
11:31
of diagnosing this
11:32
and understanding the epidemiology is still widely accepted
11:36
classification criteria and there's a lack in
11:38
associate IICD 10 code.
11:39
But the way you know, what we're realizing is that
11:43
as I'd mentioned, many different diseases in the abdomen
11:46
pelvis, what we're realizing is perhaps it they
11:48
do fit under this umbrella.
11:50
And so my prediction is that in the future,
11:52
we will be diagnosing more IgG four related disease, uh,
11:56
because we will have a better understanding of
11:58
how those other distinct disease entities actually fit under
12:01
the umbrella, uh, of over one masthead
12:04
of the IgG four related illness.
12:06
Now, there is some data to suggest how common this is.
12:09
This was a 2009 study done outta Japan
12:12
and in their cohort, anywhere from 0.28
12:15
to 1.08 cases per 100,000 in their patient population.
12:20
So not a lot of disease there up
12:22
to 1300 newly diagnosis patients per year.
12:25
So again, in the big scheme of diseases,
12:26
probably not the most high yield disease.
12:29
But as I said, my prediction is
12:31
that these rates are gonna go up.
12:32
The more we figure out, uh, what this disease is
12:34
and uh, how often perhaps it's affecting, uh,
12:37
different parts of the body from the data that we have,
12:40
it tends to affect middle and older aged males in females.
12:43
Head and neck manifestations may be more common.
12:45
It has been also described in children.
12:47
And in children it's thought that the ocular
12:49
manifestations are more common
12:52
and for risk factors, smoking as a,
12:54
it can be a risk factor in
12:55
so many illnesses may also be in risk factor in
12:58
IG four related disease.
12:59
But we don't know if it's causative
13:01
or what sort of the, uh, impact
13:03
of smoking is on that illness.
13:07
So let's look at the imaging findings, right?
13:08
We have a background of what IgG four related diseases.
13:11
Now we understand perhaps how it works, understand
13:13
that it affects many organs.
13:15
Understand that it may not be as common as we think now,
13:17
but that that is gonna go up in the future.
13:20
What are we supposed to look for, uh,
13:21
to diagnose this on imaging?
13:24
Well, the flagship organ, as I like to think of it in terms
13:26
of IgG four related disease in the
13:28
advent pelvis, is the pancreas.
13:29
I wanna spend a little bit of time
13:31
talking about the pancreas.
13:32
And within the pancreas, the disease
13:35
that can occur is called autoimmune pancreatitis.
13:39
Now it turns out that there are actually two types
13:40
of autoimmune pancreatitis, type one or type two.
13:43
Uh, there are more, uh, longer names associated with it, uh,
13:47
type one and type two if you'd
13:48
rather prefer calling it that.
13:49
But it's easier for me to remember type one and type two.
13:52
And why do you need to know this?
13:54
You need to know this because the type one autoimmune
13:56
pancreatitis is the one that's associated
13:58
with IgG four related disease.
14:00
Whereas it turns out that type two
14:02
has a more stronger association
14:04
with inflammatory bowel disease.
14:06
Now again, inflammatory bowel disease is a disease
14:07
that's not really well understood of why it occurs.
14:10
We have theories, but we don't really know why.
14:12
And, um, it's interesting
14:13
that you can perhaps get this autoimmune pancreatitis within
14:17
that disease entity.
14:18
And, and maybe there's something
14:19
to be said about a common pathophysiology there.
14:21
Now, with type one, as would be expected,
14:23
because it's related to IgG four related, uh, disease,
14:26
the IgG four levels are going to be elevated.
14:29
Whereas in type two, they're rarely elevated.
14:32
From our perspective as radiologists, the imaging,
14:35
you are unable to differentiate between these two entities.
14:37
And so when I read a report, I don't say it's type one
14:40
or type two autoimmune pancreatitis.
14:41
I usually say it's just autoimmune findings
14:43
of autoimmune pancreatitis.
14:45
But I do wanna sort of highlight the breakdown of this
14:47
because you may have a case
14:49
of autoimmune pancreatitis on imaging
14:51
that you know has no other manifestations
14:54
of IgG four related disease.
14:55
IgG four levels are not elevated.
14:57
And that is possible
14:58
because it may be the type two version,
15:00
enough autoimmune pancreatitis
15:05
from type one autoimmune pancreatitis, some
15:07
of the clinical things you want to think about patients
15:09
present in all sorts of ways.
15:10
This is what's been reported in, uh,
15:12
some small studies have been done painless,
15:14
jaice abdominal pain,
15:15
but I sort of put this list here to show you
15:17
that about a third of patients, a little over a third
15:19
of patients are asymptomatic.
15:20
So it's something that's just incidentally picked up.
15:23
So that's important. You need to keep your, uh,
15:25
eyes out sharp in order to see these incidental pickups
15:27
of autoimmune pancreatitis.
15:29
And that about 12% may present with symptoms
15:31
that have nothing to do with pancreatitis
15:32
or things up in the head and neck region.
15:34
Um, showcasing the fact that this is, you know, a disease
15:37
that is not often seen in isolation,
15:39
it's just seen in context of other things
15:41
that are going on in the body that may give you the
15:44
clinical, um, manifestations in the beginning.
15:47
Uh, but then when you start imaging the patient, you see
15:49
that there's other manifestations in the body.
15:52
Complications have been reported if does not go treated, uh,
15:55
appropriately, they can have pancreatic atrophy
15:57
with extra insufficiency
15:59
that over time may result in weight loss or even diabetes
16:02
or rare complications.
16:04
Been theory can all occur,
16:05
but as far as we know,
16:07
there's no known increased risk for pancreatic cancer.
16:09
And so there are complications associated with, you know,
16:12
atrophy of the pancreas,
16:13
but nothing that makes this patient at an increased risk
16:16
for developing pancreatic cancer.
16:19
And there's a couple of flavors of
16:20
what pancreatitis looks like.
16:21
Autoimmune pancreatitis looks like in these patients
16:23
who could be diffuse involved in the whole organ,
16:25
which is a little bit more common than focal involves a
16:28
certain aspect of it,
16:29
but often it's sort of multifocal involving
16:32
multiple aspects of the pancreas.
16:33
We're gonna look at examples of some of these,
16:35
uh, in the next few slides.
16:37
The classic, classic imaging appearance
16:39
of autoimmune pancreatitis.
16:41
It's so many people end up remembering when I ask my
16:42
trainees, is the sausage shaped pancreas.
16:45
So what does a sausage shaped pancreas actually mean?
16:48
Well, it means a pancreas that is lost, perhaps its
16:52
external loation, right?
16:54
This looks very, very flat
16:55
and smooth border rather than a normal sort
16:58
of lobulated looking pancreas.
17:00
And internally you sort of lose some of
17:03
that internal architecture of fatty peripancreatic,
17:06
fatty clefts that are interdigitating between those loation.
17:09
It looks very homogeneous, very almost expanded
17:12
and under a little bit of tension.
17:14
And classically you'll see a rind of T two
17:17
hypo intense signal surrounding the pancreas.
17:20
Now this can be quite subtle
17:21
and that's why it's important to know this exists so
17:23
that you can look specifically for it.
17:25
In this case, you can see this rind not
17:27
around the entire pancreas, but over here
17:29
and on this end as well, with a pancreas
17:31
that looks very featureless,
17:32
it looks like just like it's expanded without those loation.
17:36
One of the things to also look
17:37
for is this duct penetrating sign in that despite the fact
17:41
that you have what looks like mass like expansion
17:44
of the pancreas, you may actually see either the entire duct
17:47
or a portion of the pancreatic duct that are, you know, seen
17:50
through this area of mass like expansion.
17:52
So you can see that over here on this slide on the same
17:55
patient areas of the
17:56
pancreatic duct that you can actually see.
17:57
Now that may seem like a very small portion of it,
17:59
but believe me, this is the sort of stuff
18:01
that you're looking for that can be quite critical in
18:04
allowing you to potentially differentiate this
18:06
mass like expansion.
18:08
Um, from being a pancreatic cancer, right?
18:10
Pancreatic cancer, you're either not gonna see the duct at
18:12
all, or if you do see the duct,
18:13
it'll be quite distended, quite dilated.
18:15
Or in this case, you'll see slivers of the duct
18:17
that are quite normal in size despite the fight.
18:20
The, despite the fact that you see mass like expansion on,
18:24
uh, the T one signal of the pancreas,
18:26
usually just like you see with any other pancreatitis,
18:29
the T one signal because of the edema will be
18:31
T one hypo intense.
18:32
You will see a subtle rind, just like you see
18:34
that T two hypo intense Rhine.
18:35
If you look closely, you can see a T one hypo intense rhine
18:38
that's just hugging the edge of the pancreas.
18:40
That could be a variable size,
18:41
but often it's there in your, you know, looking
18:43
for this very subtly.
18:45
Uh, when you give post contrast images,
18:47
the pancreas won't enhance as much in the arterial phase.
18:50
Um, and uh,
18:51
the key thing though is you have your different multi-phase
18:53
is that rim, that rim you'll see will actually enhance.
18:56
And so you can see on this slide over here, you have a rim
18:59
of enhancement surround in the pancreas in the arterial
19:01
phase, but on the more delayed phase images,
19:03
that rim becomes a lot more hyperintense.
19:06
It's enhancing a lot more.
19:07
Um, and all these signs are compatible
19:09
with IgG four related disease, um, manifesting as
19:14
manifesting as autoimmune pancreatitis in this patient.
19:17
Here's another example with some of the imaging features,
19:19
autoimmune pancreatitis, but not perhaps all of them.
19:21
So you don't always see everything,
19:22
but there needs to be enough to at least, you know,
19:25
put up your antenna that this may be going on,
19:27
on this T two weighted image.
19:28
Again, mass like expansion
19:29
of the pancreas looks like it's a little bit lobular,
19:32
but it's quite smooth in border.
19:34
And does, uh, you know, lose those features
19:36
of those fatty clefts that are interdigitating through.
19:39
I'm not seeing a lot of good ductile anatomy with this,
19:41
this area on the T one weighted images, you know,
19:44
pancreas is supposed to be the brightest organ on the T one
19:46
non-contrast image here, it's quite dark
19:48
and you can see that rind a little bit over here on the T
19:51
two weighted images, but perhaps a little bit more apparent
19:53
on the T one weighted images in this case.
19:56
And here's another image of a patient
19:58
who has some congenital renal issues.
20:00
The kidneys are down in the pelvis,
20:02
but in 2023 had an imaging study showing a pancreas
20:05
that looks, you know, pretty unremarkable.
20:07
This is what a normal pancreatitis looks like.
20:08
You can see those, you know, loation,
20:10
see some fatty clefts that are going inside.
20:12
You know, this is a good look for the pancreas
20:14
otherwise doing healthy.
20:17
And a year later this happens.
20:19
You can see that the pancreas is hypo attenuating.
20:21
This is an arterial phase image.
20:23
It should be enhancing quite briskly,
20:25
but it's hypo attenuating and it looks very homogeneous.
20:28
You don't see those loation anymore,
20:29
you don't see those fatty clefts anymore.
20:31
And if you look at the periphery of the pancreas,
20:33
there's this hypo attenuating rim
20:35
that's just surrounding it, right?
20:37
You may call this regular pancreatitis,
20:39
but with regular pancreatitis you're gonna have to see fluid
20:42
that's sort of, you know, going into, um,
20:45
the adjacent per pancreatic flat, uh, fat
20:48
and looking like it's a little bit free
20:49
and sort of going in all these spaces where this one is sort
20:52
of hugging the pancreas
20:53
to a little bit more degree than you'd expect from just, uh,
20:56
interstitial pancreatitis.
20:58
But when we look at this on the mr, we can see that yes,
21:00
the pancreas is expanded, but what do we see here?
21:03
Right? We see that duct that's actually going
21:05
through this area that's unperturbed, it's a normal caliber
21:09
if you consider that maybe there's a mass over here,
21:11
this duct is certainly not dilated to support that.
21:14
Um, and you can also see that T two hypo intense tissue
21:17
that's surrounding portions of that pancreatic, uh, body
21:20
and tail on the T one, uh, pre, uh,
21:24
post contrast images, again, that portion of the pancreas
21:26
that's affected is not, uh, enhancing to the same degree
21:29
as some of the other portions of the pancreas, that rind
21:33
of tissue is enhancing.
21:35
But on the more delayed phase images, that rind
21:37
of tissue is enhancing a whole lot more.
21:39
And so all these findings are compatible
21:41
with autoimmune pancreatitis.
21:42
And a patient who just a year ago had normal pancreatic
21:45
imaging findings, but now all
21:47
of a sudden has developed autoimmune pancreatitis.
21:49
And there are imaging clues
21:50
that you can make this diagnosis prospectively,
21:53
and it's incredibly important.
21:54
The treatment of this versus regular
21:55
pancreatitis is quite different.
21:57
This will be treated with steroids, regular pancreatitis
21:59
with bowel rest and, uh, in supportive treatment perhaps.
22:03
Um, and certainly this does not look like a, you know,
22:05
you one may think this could be a cancer,
22:08
but at which for which treatment
22:09
would be drastically different.
22:12
So let's look at focal focal autoimmune pancreatitis
22:15
that proves a little bit more of a challenge can quite mimic
22:18
pancreatic cancers.
22:19
But perhaps with a little bit of clues, we can,
22:21
uh, we can tell the difference.
22:23
This was a case I saw a number
22:24
of years ago when a patient had
22:25
come in with some abdominal pain.
22:26
And you can see actually on the ultrasound
22:27
that this is the pancreas and there is hypoechoic
22:31
and it looks like a mass like
22:32
expansion of the head of the pancreas.
22:33
The rest of the pancreas looks pretty normal.
22:35
And you know, we weren't able
22:36
to make this diagnosis on the ultrasound,
22:39
but if you sort of look at it in hindsight,
22:42
look at the duct over here, yes,
22:43
it's a little bit prominent,
22:44
but the fact that you could see the duct going
22:46
through this mass like expansion should at least raise your
22:49
antenna that maybe you're not dealing
22:51
with a pancreatic cancer.
22:52
Pancreatic cancers obstruct the duct
22:54
cause a lot of dilatation.
22:55
Whereas here that's not exactly what's happening.
22:59
So they get a CT scan on the CT scan, you can see the head
23:01
of the pancreas is expanded, it's hypo attenuating.
23:04
And certainly if you saw this image,
23:06
I think nine times outta 10,
23:07
you would be worried about a pancreatic cancer.
23:10
Um, this focal mast like expansion, the head
23:12
of the pancreas, if you look at it on the Crohn's,
23:15
a very subtle sign, you can see that again,
23:17
the duct may be a little bit prominent, right?
23:19
Maybe that's four or five millimeters at most.
23:22
But for a mass that's almost, you know,
23:24
three centimeters now that duct would ex, you'd expect
23:26
that duct to be much, much more dilated.
23:28
In this case, it's only minimally dilated and very subtle.
23:31
You can see the duct that's tapering smoothly
23:34
and even see a portion of the duct
23:35
that's going into this mass like expansion over here
23:38
that looks within normal limits.
23:39
And so, um, again, there are signs, you know,
23:42
you may say can't exclude pancreatic cancer,
23:44
but there needs to be something in the back
23:46
of your head saying this is not behaving like the
23:47
typical pancreatic cancer.
23:49
And even putting focal IgG four related disease out there
23:53
and autoimmune pancreatitis out there is,
23:54
is not unreasonable because then they'll check
23:56
for those IgG four levels, they'll do the biopsy,
23:58
they'll see that it's elevated.
24:00
And this indeed turned out
24:01
to be focal autoimmune pancreatitis.
24:03
I was treated with steroids. Here's another example actually
24:07
we saw recently where, um,
24:09
patient comes in with some weight loss.
24:11
Um, and so we can see the pancreas over here.
24:14
Uh, you know, the neck of the pancreas looks okay,
24:17
the proximal body looks again towards the distal
24:19
body and tail.
24:20
It's expanded.
24:22
And I think very critically you can see that there's a rind
24:24
of hypo attenuating signal
24:27
or tissue that's surrounding this portion of the pancreas.
24:29
You know, that is a key clue that you're not dealing
24:32
with anything else but really autoimmune pancreatitis.
24:34
You look at the mr um, you know, you can see some of
24:37
that internal architecture better on the mr.
24:38
But look at that rind of T two signal
24:40
that's surrounding this pancreas.
24:41
It's T two hypot intenses,
24:43
all clues that you're dealing with.
24:44
Autoimmune pancreatitis, another case
24:48
of autoimmune pancreatitis involving fally.
24:50
The pancreatic tail, you know,
24:51
the pancreatic body neck region looks pretty okay.
24:54
The tail fally expanded.
24:55
And again, that rind of hypo attenuating content
24:58
that's just hugging the pancreas.
24:59
All clues that you're dealing with autoimmune pancreatitis.
25:07
So what about, um, treatment?
25:10
Well, luckily, type one
25:11
and type two autoimmune pancreatitis will both respond
25:14
to glucocorticoid therapy.
25:16
The data that we have out here suggests that there's more
25:18
of a relapse though with type one autoimmune pancreatitis,
25:22
the one that's associated with IgG four related disease.
25:24
And if you look at it in terms of normalization
25:27
of imaging findings, about two thirds of patients
25:29
with type one autoimmune pancreatitis will have
25:31
normalization of imaging findings.
25:32
Or about 86%
25:33
of type two pancreatitis will normalize those imaging
25:36
findings, um, over a period of time with steroids.
25:42
And so this is what pre and post treatment looks like.
25:43
This is one of the examples that I gave
25:44
of autoimmune pancreatitis, expanded pancreas,
25:47
a very subtle T two hypotensive rim.
25:48
This is what it looks like a T one weighted images
25:50
and the t uh, one post contrast images hypo
25:52
enhancement post-treatment.
25:54
You can see that that expansion, it's not expanded anymore.
25:57
It doesn't look massive. It looks almost like a normal
25:59
looking pancreas, um,
26:00
similar in the T one weighted sequence.
26:02
And look how nicely it's enhancing now.
26:03
And so these are the features you're looking
26:05
to see on the post-treatment.
26:07
Um, is it less expanded? Is that Ryan gone away?
26:09
Is it enhancing appropriately?
26:10
This all signifies successful treatment.
26:14
Here's another example. This is
26:15
that focal autoimmune pancreatitis case
26:17
that one could easily mistake for pancreatic cancer.
26:20
We can see that, uh, it looks mass like over here.
26:23
We, you know, it was treated with, uh,
26:25
steroids and now it's gone.
26:26
Yeah, this is the same patient.
26:28
I kid you not at the same slice, you know,
26:29
with the right renal artery there
26:31
and you just don't see that, uh, finding anymore.
26:36
So there's a question in the q
26:38
and a, uh, maybe I'll get to that at the end.
26:41
So what are some pitfalls, right?
26:42
So what are some instances where it kind
26:44
of looks like autoimmune pancreatitis,
26:45
but it turns out it's not going
26:46
to be autoimmune pancreatitis.
26:47
This is a case where, uh, one of the pitfalls,
26:50
so you can see that again, the body entail
26:52
of pancreas is diffusely involved.
26:53
It looks very mass like.
26:55
Um, and one of the considerations
26:57
of this case was autoimmune pancreatitis.
26:59
This turned out to be an adenocarcinoma.
27:02
So let's look back now
27:03
and figure out what about this is different than those cases
27:05
of autoimmune pancreatitis that I've shown.
27:07
And one of the things I think you can look for
27:09
to perhaps favor one of the other in an instance like this,
27:12
is the heterogeneity within the pancreatic
27:14
parenchyma itself, right?
27:15
If you look at autoimmune pancreatitis usually is very
27:18
homogeneous mass, like expansile
27:20
as it involves the pancreas.
27:22
Whereas here, there's different attenuation within this here
27:24
that's a little bit more low in attenuation here
27:26
is higher in attenuation.
27:28
And so that heterogeneity typically, uh, is not seen
27:31
with autoimmune pancreatitis,
27:32
but can be seen with um, sort of expansile and, uh, and,
27:36
and a long length of carcinoma.
27:40
There's another case where this is, uh, you know,
27:42
a focal area of abnormality involved in the unseed process.
27:45
Um, on the T one weighted post contrast image looks a little
27:48
bit hypo enhancing, maybe looks a little bit mass like, um,
27:53
and, uh, you know, this was a case
27:54
of pancreatic adenocarcinoma.
27:55
And so it's important to, uh, ensure that, you know,
27:59
you're not gonna be calling anything focal,
28:01
you see from now on as autoimmune pancreatitis.
28:03
No common things being common.
28:05
They're probably gonna be cancers.
28:06
But you need to look for the imaging clues, which is
28:09
what is the duct doing in relation to the mass?
28:11
Is it passing through it?
28:12
Is it distended
28:14
to the degree you think it would be distended given that,
28:17
you know, an adenocarcinoma really distends the duct?
28:20
Is there a rind of tissue around it?
28:22
And suggesting it and not being right is not a failure.
28:25
It just means that there needs
28:26
to be a little bit more of a workup to be done.
28:28
Um, and if you're right about it,
28:30
you can really save the patient, uh, in a lot of trouble.
28:34
And this of course is a case where, you know,
28:36
it doesn't quite look like autoimmune pancreatitis,
28:38
but again, it's a focal finding.
28:39
It's a little bit T two hyperintense dark
28:41
on the T one weighted images.
28:42
This was just a case of focal pancreatitis
28:44
involving the unseed process.
28:46
Um, you know, with a hot immune pancreatitis,
28:48
you'd expect there to be more homogeneous signal
28:50
not as bright as this.
28:52
And, uh, and this turned out
28:53
to just be your good old fashioned, uh, uh,
28:56
focal pancreatitis.
28:59
And again, another question I will promise, get
29:01
to the questions in the, in the end.
29:04
So let's look at some other manifestations.
29:05
We spent a lot of times looking at the pancreas.
29:08
So that's where my eyes go when I look for cases
29:10
of potentially, uh, you know,
29:11
IgG four related disease in the abdomen pelvis.
29:13
But I have to say, increasingly my eyes have also been
29:16
going to the biliary system.
29:17
So what happens in the biliary system,
29:19
it turns out you get an IDG four related sclerosing
29:22
cholangitis, or it's the second most common manifestation
29:26
of IgG four related disease in the abdomen
29:28
after autoimmune pancreatitis.
29:30
It often can occur
29:31
with autoimmune pancreatitis, but guess what?
29:32
In about 8% of patients that'll occur in isolation.
29:35
So we need to know what this looks like.
29:37
Um, you know, in, in independent of, uh, its relationship
29:40
with autoimmune pancreatitis.
29:42
And this can cause symptoms
29:43
as anything in the biliary tree can cause symptoms,
29:45
you know, obstructive jaundice, abdominal pain, weight loss.
29:47
If it obstructs a biliary tree, you know,
29:49
it can certainly cause symptoms.
29:50
So this is less likely to be just an asymptomatic thing.
29:55
And really the manifestation is strictures.
29:59
It's most commonly seen in the distal common bile duct,
30:02
but it's been reported in the extra intra pad ducts
30:04
and the extrap pad ducts the key thing here, just like
30:07
with autoimmune pancreatitis, yes you have a stricture, yes,
30:11
you'll maybe get some prominence of the upstream ducts,
30:13
but it's not gonna be to the same degree as you would expect
30:16
for a cholangiocarcinoma.
30:17
It's gonna be a little bit prominent.
30:19
The stricter itself will be smooth,
30:21
there'll be circumferential wall thickening and enhancement,
30:24
and generally will be a longer segment than you would expect
30:27
for say a cholangiocarcinoma malignant stricture.
30:30
So let's look at these two cases.
30:32
Here we can see, uh,
30:33
post contrast CTM is look at the stricter,
30:35
very smooth it's circumferential wall
30:37
thickening and enhancement.
30:39
And it's for a generally a, you know, a longer length.
30:41
We can see it on this image
30:42
and on this image as well,
30:43
how it's involving quite a long portion of the biliary tree.
30:47
And for the degree that it's involving the biliary tree,
30:50
there's not a lot of ductile dilatation.
30:51
Yes, it's a little bit prominent,
30:53
but if this is a clan, see much more pronounced narrowing
30:56
and much more ductal dilatation.
30:58
And so sure you need to do an ERCP to exclude a cholangio.
31:02
But think about other things.
31:03
Could this be IgG four related disease?
31:06
Now the, uh, eagle eye, uh, observers, um,
31:09
will look at this slide and say, listen,
31:10
there are other manifestations
31:11
of IgG four related disease here.
31:13
Look at the pancreas, right?
31:15
A long segment of pancreas, it's hypo attenuating.
31:17
And yes, you may think that's your regular pancreatitis.
31:20
Yes, you may think that that's an adenocarcinoma,
31:22
but look at the duct.
31:24
You see portions of the duct that are preserved.
31:26
And so putting these two findings together really need
31:28
to put out the possibility of IgG four related disease.
31:32
We look at this on mr, this is, uh,
31:34
I think the same patient we look at on the mr.
31:36
You can see again, smooth long segment thickening of, um,
31:40
of enhancement involving the wall of the biliary tree.
31:43
And look at this ERCP, right? You know, there it is.
31:46
Get quite narrowed over here.
31:47
This very, very thin area over here.
31:48
But despite that, yes, the ducts are dilated,
31:51
but certainly not to the same degree
31:53
that we would expect a cholangiocarcinoma
31:55
to dilate those ducks.
31:58
This is a very interesting case we saw, uh,
32:00
relatively recently where look how you know thick,
32:03
the biliary tree is over here, right?
32:06
Look at that, uh, degree
32:07
of thickness involving the extrap pad,
32:08
biliary tree involving the cystic duct remnant in this
32:12
patient who had, um, uh, post chole cystectomy.
32:16
And if you look at cross sections of this, look
32:18
how thick it is on the arterial phase images showing again,
32:20
that more delayed enhancement.
32:22
Where do we remember seeing that?
32:23
We remember seeing that with
32:24
autoimmune pancreatitis as well.
32:26
And so I think, again, it would be tough
32:27
to call this prospectively as IgG four related disease,
32:31
but there's gotta be clues to suggest
32:33
that this is not gonna be a cholangiocarcinoma.
32:35
This certainly doesn't look like other cholan ities
32:37
that you're used to and
32:39
that the T two signal is relatively dark
32:40
and that you have this delayed
32:42
enhancement associated with it.
32:44
Here's another example of, uh, a person
32:47
with a smooth long stricture over here.
32:49
And yes, there's some degree of ductal
32:50
dilatation associated with that.
32:51
And you know, you may wanna consider a cholangiocarcinoma,
32:54
but if you look at the concomitant CT on this patient,
32:57
you'll see that the pancreas has this rind of, uh,
33:00
hypo attenuating tissue that's surrounding it.
33:02
And that putting that together,
33:04
this is a biliary stricture in a patient
33:06
who also has autoimmune pancreatitis in this patient
33:09
with IHG four related disease
33:11
of the abdomen, uh, and pelvis.
33:17
Alright, Now for treatment, again,
33:21
steroids is the first line treatment
33:22
and it may respond to steroid therapy, the, uh, the sclero
33:26
and cholangitis associated with IgG four related disease.
33:28
But there is a high risk of relapse, right?
33:30
So, uh, may not be as effective as we would like.
33:33
Let's give an example of what this looks like.
33:35
This is another patient with smooth long regions of, uh,
33:38
mural wall thickening, um,
33:40
relatively hypot intense on the T two weighted images.
33:43
This is a patient with confirmed value
33:44
G four related disease.
33:45
You can see on the MRCP, you don't even see the duct, uh,
33:48
the extrap pad, bi tree 'cause it's so narrowed.
33:51
Uh, but again, de despite the fact that it's narrowed,
33:53
you don't see a lot of intrahepatic ductal dilatation,
33:55
which is a sign you're dealing with I
33:57
IgG four related disease.
33:58
But look at the post-treatment, you know, that ductal, uh,
34:01
thickening has definitely improved.
34:03
And if you look at the MRCP, you can actually see portions
34:06
of the lumen now that you couldn't see before.
34:07
And so this tells you that there has been some, um,
34:10
treatment effect based on, uh, the steroid administration.
34:17
Some pitfalls, you know, one you want
34:19
to make sure you don't miss is cholangiocarcinoma.
34:21
You can see in this instance there's a focal region, right?
34:24
Not as long segment. This one ends to be focal.
34:26
It's in the distal common bile duct causing a much more
34:28
abrupt narrowing and quite significant upstream ductal
34:32
dilatation as when you see something like this,
34:34
you're gonna be more worried about a cholangiocarcinoma.
34:36
There's no real signs here to suggests that you're dealing
34:39
with IHT four related disease.
34:41
Um, it's much more narrowed
34:42
and causing a lot more ductile dilatation.
34:45
And then maybe you think of regular, you know,
34:46
primary sclero and cholangitis.
34:48
But I think you'd be able to differentiate those, you know,
34:50
the classic primary sclerose and cholangitis.
34:52
Very typical picture of multifocal regions of intra hepatic
34:57
and extrap pad ductal narrowing due to strictures
35:00
and then dilatation narrowing
35:01
and dilatation narrowing and dilatation.
35:03
As you can see here, um, with the RCP
35:05
or even MRM RCP showing areas of beating.
35:08
All that would be not really typical
35:10
of IgG four related disease.
35:11
IG four, you're really dealing
35:13
with smooth circumferential narrowing
35:15
of a relatively long segment without the
35:18
expected upstream ductal dilatation.
35:23
So pancreas, biliary system and retroperitoneum.
35:27
I know it's a question on retro perineum in the chat,
35:29
so we'll address them, uh, after the session.
35:32
So IgG four related retroperitoneal fibrosis,
35:36
that's the anti in the retroperitoneum.
35:37
It can occur again with autoimmune pancreatitis,
35:39
but again, it could be isolated about a fifth of cases.
35:41
So it's important to understand
35:43
that if you see retroperitoneal fibrosis,
35:45
maybe you're dealing with IG four related disease
35:48
and you know, IG four related disease may, uh,
35:51
retroperitoneal fibrosis as an entity
35:53
may be due to a number of reasons.
35:55
Um, most commonly it's idiopathic
35:57
what we used to call orman's disease.
35:58
But it's increasingly thought that the idiopathic
36:01
or orman's disease,
36:02
however you wanna think about it,
36:05
fits under the IHG four related family of diseases.
36:09
And the others causes are all secondary,
36:11
which we won't get into.
36:14
So what are we looking for? Retro peroneal fibrosis.
36:16
We're looking for an ill-defined almost sheetlike mass
36:20
that surrounds typically the anterior
36:22
and lateral aspects of the abdominal aorta.
36:25
Classically, it spares the posterior border of the aorta
36:29
and it can certainly involve many segments
36:31
of the abdominal aorta.
36:32
But classically, the epicenter of a lot of this is
36:34
that the takeoff of the IMA, right?
36:36
That's where I like to think about where my eyes go
36:39
to see IG four related, uh, to see retro perial fibrosis.
36:42
And it sort of classically goes coddly from there involving
36:46
the common niac vessels.
36:50
And oftentimes, you know, it sits there
36:53
and one doesn't recognize it.
36:54
And this tissue sort of grows over a period of time
36:57
and it starts to pull the ureters towards it.
37:00
So you get this classic medial deviation of the ureters.
37:03
And it is really often the urinary problems
37:07
that IgG four related retroperitoneal fibrosis.
37:09
Cause that brings the patient to, uh, clinical attention,
37:13
um, because it can result in obstructive neuropathy.
37:17
So you can see here, there is tissue in this location.
37:19
It's pulling the ureter I medially,
37:21
and in another case, ureter is being pulled immediately
37:23
resulting in hydro necrosis.
37:24
Yet another case of, uh, CT urogram.
37:26
We see this mass like retroperitoneal tissue.
37:29
This is all RP fibrosis pulling this ureter medially, uh,
37:33
similarly with this one,
37:34
but this one, uh, has a delayed nephro.
37:36
So you're not seeing that contrast being
37:38
excreted by the ureter.
37:40
And just as it can do this with the ureters, it can do this
37:42
with surrounding vessels, particularly the veins.
37:45
And so again, soft tissue
37:46
that's surrounding the abdominal aorta here,
37:48
pulling the ureters mely resulting hydronephrosis.
37:51
But you see a little bit more vessels here than you should
37:54
next to the IVC
37:55
and down below in the pelvis, lots of collateral vessels
37:58
and in fact so much venous stasis.
38:00
There's a deep vein thrombus in this instance.
38:02
And so, you know, look at the vessels again, um, in addition
38:05
to the ureters to see what the RP fibrosis is doing,
38:08
uh, to those vessels.
38:11
And one of the things that's important to remember is
38:13
that it's a dynamic disease, right?
38:15
There's an early stage of retroperitoneal fibrosis,
38:17
which is a much more endemic tissue that's more vascular.
38:20
And then there's a late stage
38:21
where you have the fibrosis kick in,
38:24
just like IgG four related disease.
38:26
You know, it causes inflammation, which is the early stage
38:28
and the late stage where the fibrosis kicks in.
38:30
Um, and if you were to catch it in the early stage,
38:34
that's when the RP fibrosis will respond to medical therapy
38:37
that a steroids, if you catch in the late states,
38:39
you won't respond as much.
38:40
And perhaps in that instance, you'll need
38:42
to really sort out surgical options in order to, you know,
38:45
maybe reroute some of the um, uh, ureters
38:49
or vessels that if, uh, the,
38:51
the fibrotic tissue is obstructing.
38:54
And so this is an example of what sort
38:55
of the more chronic stage will look like.
38:57
It's certainly T one hypo intense
38:59
and the T two signal is relatively hypo intense.
39:01
Yes, it's a little bit brighter than the muscle here,
39:03
but relatively hypo intense even on this image.
39:05
And when you give contrast, you're not seeing a lot
39:08
of hyper vascularity associated with this.
39:10
And I want you then to contrast this
39:13
with more active disease
39:14
where you can clearly see in this instance,
39:16
the T two signal is a lot more hyper intense,
39:18
certainly with respect to the muscle.
39:20
T one signal doesn't really change
39:21
whether it's active or chronic.
39:22
Uh, but look at the t uh, post contrast image.
39:26
Much, much more hypervascular.
39:28
And when you see instances like this, you know,
39:31
I will tell in my report
39:32
that this is probably the active stage of the disease.
39:34
And what I'm trying to convey to my provider is
39:36
that this may respond to OID therapy,
39:38
whereas the other stage may or may not.
39:40
And so, uh, I think that gives some good information
39:43
to our referring providers.
39:45
And so again, retroperitoneal fibrosis is sort
39:47
of the classic IgG four related manifestation
39:51
of disease in the retroperitoneum,
39:52
but you can get fibrotic tissue in other locations
39:55
beyond the classic location of RP fibrosis.
39:57
This was an interesting instance of a patient who had,
39:59
you know, multisystem IgG four related disease
40:02
who ended up just having a mass in the retroperitoneum,
40:05
but adjacent to the kidney and the perinephric fat.
40:06
You can see it on the t uh, the CT image
40:09
and, uh, a little bit dark on the T two weighted images
40:11
and with some variable degree of enhancement.
40:13
And, um, so just to, to know that, you know,
40:16
that fibrotic tissue can occur in other locations in the
40:19
retroperitoneum and not necessarily in
40:21
that classic RRP fibrosis location.
40:24
Some pitfalls. One thing you always need
40:26
to remember is this disease entity.
40:28
Yes, there's soft tissue in the
40:29
retroperitoneum, but look what it's doing.
40:31
It's sort of lifting the aorta off the spine.
40:35
It's enveloping some of the vessels over here,
40:37
but despite the fact that it's doing that, not causing a lot
40:40
of, uh, obstruction
40:42
or certainly not a delayed nephro ground.
40:43
When you see a disease entity doing this,
40:45
always have to think of lymphoma.
40:47
And I would favor lymphoma in this instance
40:49
of her RP fibrosis.
40:52
So those are the top three ones that I always want.
40:54
I always focus on the, the pancreas, a biliary tree,
40:57
and the retroperitoneum.
40:59
But you know, once you've sort of mastered those
41:01
and memorized that, that's where you need to look.
41:02
It's important to then start branching out
41:04
and look at some other areas that are more niche.
41:07
Um, but the more you look,
41:08
the more you're gonna find disease involvement.
41:10
And I've certainly, um,
41:12
benefited from looking at these areas in, in, in
41:14
and in very many cases of IG four related disease.
41:18
And so IG four related disease can
41:19
also cause the vasculitis.
41:20
It often involves. The aortic can also involve the iliac
41:22
vessels and it can involve other body parts,
41:25
whether it's in the heart and the corners or the head
41:26
and neck region in the carotids.
41:28
And it's more often than you'd think in about,
41:30
almost about a quarter a patient
41:31
with IG four related disease.
41:33
They'll have some degree of vasculitis
41:34
and there are complications associated with that, uh,
41:37
that are similar to any complications associated
41:39
with vasculitis, whether it's stenosis,
41:41
whether it's dissections, whether it's aneurysms that form.
41:43
And so one always needs
41:44
to be on the lookout for these things.
41:47
And so what you're gonna end up looking for is things
41:50
of vasculitis, right?
41:51
And a patient with, you know,
41:52
perhaps IgG four related disease.
41:54
You can see circumferential typically wall thickening
41:57
with variable T two signal, depending on the degree
41:59
of activity of the disease
42:00
and enhancement that is more pronounced on the delayed phase
42:04
imaging in general, right?
42:07
And if you do end up doing a PET imaging
42:09
for whatever reason, these patients,
42:11
that wall will be ftg avid.
42:12
So it's the same patient. You can see
42:14
how avid the ftg wall is normally should
42:16
not be this ftg avid.
42:19
This is another interesting, uh, this is interesting case.
42:21
This is actually, if you recall,
42:22
there was a patient I showed you in the autoimmune
42:24
pancreatitis case, um, that had kidneys
42:27
that were in the pelvis who in 2023 had relatively normal
42:30
looking pancreas and then a year later
42:32
developed autoimmune pancreatitis.
42:33
Well, this is what this patient's pelvis
42:35
looked like in 2023.
42:36
You know, this is the pelvic kidney
42:38
and arteries that you know, you would not really comment on.
42:41
But in 2024 when you developed the autoimmune pancreatitis,
42:45
you look at the arteries very subtly.
42:47
Look at that soft tissue surrounding the I iliac artery.
42:49
Certainly, maybe there was something there you'd never call
42:52
it in 2023, but definitely a lot more in 2024.
42:55
And look at this soft tissue, again, not callable,
42:57
I think in 2023,
42:58
but now there's like soft tissue thickening
43:01
with mass like enlargement of some of that soft tissue
43:03
that developed just a year later at the same time point
43:06
that the autoimmune pancreatitis developed.
43:08
And so if you just focus on the pancreas,
43:11
you'd be missing what's going on
43:12
in some of the other organ systems.
43:13
And this patient ended up getting a pet ct.
43:14
You could see very clearly that there's ftg avidity
43:17
associated with that soft tissue.
43:19
And this is suggestive of a vasculitis associated with, um,
43:23
with auto, with IgG four related disease.
43:27
And this also can respond to therapy.
43:29
And so when you look at, you know,
43:31
the post-treatment studies,
43:32
look at all these different organs, this is
43:33
what it looked like pre-treatment in one of our patients
43:36
with, uh, known IgG four related, uh,
43:38
vasculitis and post-treatment.
43:39
Certainly that wall thickening has improved.
43:41
Um, and sort of at the two o'clock position
43:44
and even at the five o'clock position,
43:46
there's been some studies that suggest that with the,
43:49
with the treatment, the luminal, um, actually the lumin
43:52
of the vessel dilates.
43:53
And so, uh, they've been thought
43:55
that maybe some alternative therapies are better if
43:57
that ends up happening, um, in the imaging study.
44:00
So it's important to not only look at if the wall is
44:03
improving in thickness, but is there, you know,
44:05
aneurysm development.
44:06
And if that's the case, maybe that tells the providers
44:09
that need to switch therapies.
44:15
Now one of the, um, issues is that, uh, you know,
44:18
all we're seeing is sort of this, uh, this wall thickening
44:21
and it's often nonspecific
44:23
and some of the other vasculitis associated with say, lupus
44:26
or takasu arteritis
44:28
or joint cell arteritis can look quite similar.
44:30
And so if I just see the vasculitis, I'm not gonna go ahead
44:33
and suggest IgG four related disease,
44:35
although I may put that in my differential.
44:36
Yeah, IG four related disease can do that.
44:38
But excuse me,
44:40
the more important thing from my perspective is if you sense
44:42
that there's IgG four related disease in the abdomen pelvis,
44:45
or if you know the patient has IG four related disease
44:47
elsewhere, that you look at the vessels.
44:50
And that if you do then see thickening in that context, that
44:52
that may be vasculitis associated with that.
44:55
One of the other things that can potentially look like this
44:57
is infectious aortitis,
44:58
but I will say that infectious aortitis usually
45:00
presents a little bit differently.
45:02
This is a patient who had infectious aortitis.
45:04
We'll see that instead of being smooth
45:06
and circumferential, usually more eccentric
45:09
as you can see over here, this wall thickening involving
45:11
just sort of the, uh, left aspect
45:14
of the aorta in this instance.
45:15
And you can see the, the, the,
45:17
the enhancement associated of that.
45:18
And you typically have a history of fever leukocytosis.
45:21
Whereas with IG four related disease,
45:23
remember this is insidious onset.
45:24
You know, patients may have vague symptoms of weight loss
45:28
and maybe some abdominal pain.
45:29
Typically not very acute symptoms, uh,
45:32
in IG four related disease.
45:35
How about the kidneys? Right?
45:37
So in doing some of this work, uh, I come to realize that,
45:40
you know, not uncommonly you'll see real
45:43
manifestations of this disease.
45:44
And there have been some people who've looked at this in the
45:46
literature, um,
45:48
and they've seen that in their cohort of 153 patients
45:50
with I DG four LA disease,
45:52
actually about 50% had some renal involvement
45:54
and histologically that manifests
45:56
as tubular interstitial nephritis.
45:58
But the important stat I think in that context is
46:00
that almost all the patients who had renal involvement
46:02
demonstrated extra renal involvement.
46:04
So isolated renal involvement is really, really rare.
46:06
Oftentimes you're gonna see in the context
46:08
of other disease happening, um,
46:10
and usually the symptoms arise from the extra renal
46:13
involvement, but kidney dysfunction has been also reported,
46:16
um, you know, with renal
46:17
involvement, IgG four related disease.
46:19
And so what are you gonna look for in the kidneys?
46:21
Well, you're gonna look for these T two hypo intense foci
46:24
that are typically rounded
46:26
or maybe wet shaped, um, often small, often sub centimeter,
46:30
and they're the periphery of the, uh, of the kidney.
46:32
You can see one over here, one over here.
46:34
Um, it's also been reported
46:36
to have diffuse patchy involvement.
46:37
But from the experience that I have,
46:38
often you're seeing these round to wet shape matches
46:42
masses surrounding the periphery
46:44
of the kidney of variable size.
46:48
Often they're T one hi intenses, they don't enhance a lot.
46:51
Um, but if you do do more delayed phase images,
46:53
you may see progressive enhancements.
46:55
So in this case, you're not really seeing it much on the T
46:56
one weighted images and it's hypo enhancing on the
46:59
post contrast images.
47:02
This is an interesting case of a patient who had a pre
47:05
and post contrast study
47:06
and showing multiple masses
47:08
within the periphery of the kidney.
47:09
This one looks a little bit rounded.
47:11
Uh, this would, you know, wet shape
47:12
with rounded borders over here as well.
47:14
And you know, if you were to look at this, uh, you know,
47:16
there's many things you could, you could
47:17
suggest that this could be.
47:19
Maybe this is lymphoma, you know, maybe this is, you know,
47:22
something exotic like sarcoid.
47:23
Could it be a met from another disease?
47:25
Uh, if the patient fever leukocytosis,
47:27
maybe you consider pyelonephritis,
47:29
or this does look more mass like than just regular pilo.
47:32
But you know, we really don't know what it is.
47:36
But if we were to have looked at this case,
47:39
and we did, now in retrospect,
47:40
'cause this turned out to be IgG four related disease
47:42
and the kidneys on biopsy, you can see
47:44
that the biliary tree is not completely normal.
47:47
Look at this enhancement.
47:49
This, you know, relatively long segment of wall thickening
47:52
and enhanced involvement, bi tree.
47:54
Uh, you know, what we've learned is that that's
47:56
what IGT four sclerosis and cholangitis can look like.
47:58
And you know, it's not gonna cause any real ductal
48:01
dilatation or maybe minimal.
48:02
And so that's what's not gonna come to our attention.
48:03
All you're looking for is that hyper enhancement
48:06
of a long segment of biliary tree.
48:08
And so I think if you saw something like this
48:10
with these renal masses, you know,
48:12
putting IgG four related disease out there
48:13
would be very, very reasonable.
48:15
In that case, you would've been correct.
48:18
And another instance in this case,
48:20
if we looked at the aorta, you know, remember, you know,
48:22
seeing wall thickening of the aorta, it doesn't mean much.
48:25
But if you see in the context of other illnesses
48:27
that suggest IgG four lay disease, then you can suggest
48:30
that maybe that's what's going on here.
48:31
Look at this wall. Look how thickened it is.
48:33
This is not normal for an abdominal aorta.
48:35
And so circumferential thickening here,
48:37
enhancement involve biliary tree, multiple renal mass,
48:40
you have three organ systems here,
48:42
and this was a path proven IgG four related disease, uh,
48:46
on biopsy in the kidneys,
48:47
all would respond to steroid therapy.
48:51
Here's another instance where,
48:52
again, multiple masses, right?
48:53
You look at this, you're saved to phenal map lymphoma mets.
48:56
You know, I don't think if I were
48:57
to look at this in isolation, I would think
48:58
of IgG four related disease.
49:01
But if I look at other organs,
49:03
perhaps I can get closer to that diagnosis.
49:05
Again, the biliary tree.
49:06
Um, you know, an area that I think, um, you know,
49:09
one really needs to look, uh, you know, look closely at.
49:11
You can see that this biliary tree here looks a little bit
49:14
dilated, but the wall is fine.
49:15
Look what the wall does over here.
49:16
It's quite thickened, it's quite hyper enhancing.
49:18
And so if you see these masses in conjunction with this,
49:21
I mean, you, you know, you need to start thinking
49:23
that this be IG four related disease.
49:25
And this person in fact, also had very subtle findings
49:27
of focal, um,
49:28
autoimmune pancreatitis involving the head of the pancreas.
49:31
Now, I'd be very hard pressed to, to, to, to tell you
49:34
that this is what a diagnosis
49:35
that I would've made prospectively.
49:37
But it does look T one hypo intense over here at the SID
49:40
process of the respect to the rest of the pancreas.
49:42
You can see the duct going right through it.
49:44
And so in retrospect, probably had a touch
49:45
of autoimmune pancreatitis,
49:46
but this was also a path proven IgG four
49:49
related disease in the kidneys.
49:52
And what does treatment look like?
49:53
This will also respond to steroid therapy.
49:54
This was a IgG four related disease here
49:56
and over here, post-treatment, these things will go away,
49:59
and often you'll see an area of scarring in, in that region
50:02
where that illness, uh, was affected.
50:08
What are some of the things that can look like this?
50:09
We've talked about some piot Nephritis is one of them.
50:12
Um, I think clinical context in that is key.
50:14
Usually the T two signal is a little bit brighter
50:15
with piot nephritis.
50:16
Here you can see that the 'cause of the edema,
50:18
it's a little bit brighter than you would see
50:20
with IgG four related disease,
50:21
but certainly it can look like that.
50:22
And so check the urinalysis, check the urinary symptoms
50:25
to exclude pilot nephritis.
50:27
That's an easy thing to suggest.
50:28
Um, this is an infarct over here.
50:30
Usually those are more wet shaped and have no enhancement
50:33
or as IgG four have hypo enhancement.
50:36
And so, uh, you know, and,
50:38
and oftentimes with infarct, you can see that the rim sign
50:40
of, uh, the rim of this preserved
50:41
or IgG four, you don't see that, uh, you know,
50:44
you don't see the rim scientifically.
50:45
And so, um, should be easier to make the diagnosis
50:49
of an infarct, uh,
50:50
and differentiate from IgG four related disease.
50:53
Lymphoma can be a little bit harder, you know, um,
50:55
lymphoma typically, you know,
50:57
in this case is perinephric tissue,
50:58
but can cause masses in the kidneys
51:00
and, um, certainly is one
51:02
of the things you need to put out there.
51:03
Usually lymphoma of the kidneys,
51:04
you'll see adenopathy elsewhere,
51:06
but if you don't see adenopathy elsewhere,
51:08
it's gonna be tough to differentiate
51:09
from IgG four related disease.
51:11
In that instance. To make my diagnosis
51:13
of IgG four related disease, I'm looking at the pancreas,
51:17
the vessels, the retroperitoneum
51:18
and the biliary tree very, very closely.
51:19
And if I see a finding there, I'll, uh,
51:21
I'll favor IgG four related disease.
51:24
And finally, mets. You know,
51:25
mets is typically easier in the sense that you have a,
51:28
you know, a history of primary,
51:29
you know, you know neoplasms.
51:31
And if you see new mass that develop in that context, uh,
51:34
such as in this case of lung cancer,
51:35
you're gonna call that mets.
51:36
But as you can see, they can look like
51:38
IgG four related disease, uh,
51:40
as I've shown you in some prior slides.
51:44
How about other organs? How about the prostate gland?
51:46
It turns out that it can affect the prostate gland,
51:49
but this is only recently discovered,
51:51
only first reported in 2006,
51:53
but studies show that it may affect up to 15% of patients
51:56
who have IG four related disease.
51:58
So certainly very legitimate organ involvement.
52:01
Uh, as we're learning more about it, you know,
52:04
patients can present with lower urinary tract symptoms.
52:06
PSA levels can be variable.
52:07
None of that's really gonna help you unfortunately.
52:10
And I will, um, you know, uh, submit to you
52:13
that the imaging findings may not always really help either.
52:17
A few things have been described, either you get this sort
52:19
of diffuse T two hypot intense signal that, um,
52:24
in the peripheral zone
52:25
and in the transition zone that sort
52:26
of melds the anatomy across one another.
52:29
So say you don't see any zonal anatomy at all, uh,
52:32
you can also see findings in just the peripheral zone
52:34
that are diffuse or foal T two hypo intense
52:37
with restricted diffusion.
52:38
You can also see focal findings in the peripheral zone
52:41
that are T two hypotensive without restricted diffusion.
52:43
So you can see anything, right?
52:44
So I think if you see very homogeneous involvement like
52:47
that, that's one thing to look out for.
52:48
Certainly in this instance, there's homogeneous involvement
52:51
and involvement more fo in the peripheral zone,
52:52
the restricted diffusion, you know,
52:54
you would definitely call this, uh, you know,
52:57
prostate cancer, 9.9 times out of a 10.
53:00
The only instance in which you may relate, you know,
53:03
suggest IgG four related disease as we did in this instance
53:06
because the patients had other manifestations of it
53:09
and, uh, in the abdomen pelvis.
53:11
And so we said in that context,
53:12
maybe this could be IgG four related disease.
53:16
And if you do PET imaging, uh, appear
53:17
with PMSA pet fortunately doesn't really help in this case,
53:21
can be showed diffuse uptake.
53:22
And so that didn't really help us in this instance.
53:24
Biopsy would ultimately show this was all
53:26
IgG four related disease.
53:28
As I said, you know, prostate cancer can look identical.
53:30
You look at this case, there's diffuse T two,
53:32
hypo 10 signal the peripheral zone with areas of, uh,
53:35
you know, what look like restricted diffusion.
53:37
I don't want people to come out
53:39
of this seminar calling this IgG four related disease.
53:41
You're gonna call this cancer but only think
53:43
about IG four related disease.
53:44
If potentially there's any clues that there may be, uh,
53:47
underlying IgG four related disease, um, you know,
53:50
in this patient, just look
53:54
at anything in the chat box.
53:55
Alright? We'll address those questions in a bit.
53:57
And this instance is another pitfall, which, uh,
54:00
I think you know, is one
54:01
that we are increasingly recognizing to the point
54:03
where we can perhaps make this diagnosis prospectively.
54:06
You can see there are focal areas
54:07
of T two hypo intensity in the peripheral zone,
54:09
but there are a lot more hypo intenses
54:11
that we would see from prostate cancer, um,
54:14
or even IG four related disease.
54:15
In these instances, they don't actually restrict.
54:17
And when you see, you know, many sort of focal areas,
54:20
typically there are many that are that hypo intense.
54:23
You want to think about BCG related prostatitis.
54:26
And where did the BCG come from?
54:27
Well, a lot of patients with, uh, bladder cancer
54:30
actually get treated, uh, with BCG injections.
54:33
And in the context of doing that can get some, um, spread
54:37
of the BCG depositing within the prostate gland.
54:40
And then these BCG, uh, you know, prostatitis
54:42
and granulomas can develop
54:44
that can look quite T two hypot intense.
54:46
Again, you probably will end up calling this cancer
54:48
and need a biopsy to prove it,
54:49
but, um, prospectively you can at least suggest this
54:52
diagnosis based on that hypo intensity T two signal
54:57
peritoneum, right?
54:58
So let's talk about, you know,
54:59
talk about exotic areas where this can develop.
55:01
This is a rare area
55:02
where IgG four release disease can develop
55:05
and, uh, it's going
55:06
to be indistinguishable from carcinomatosis,
55:09
particularly if you're seeing it as the only isolated
55:11
finding or if you're not seeing anything else in the
55:13
pancreas or the biliary tree or, uh, in the kidneys.
55:16
If you just see this, you know, soft tissue in the para
55:18
and you're gonna call a carcinomatosis, 10 times outta 10
55:21
can also present as a mesenteric mass.
55:22
And there's a whole differential for
55:23
what mesenteric masses can be.
55:25
And so, case in point, this example was a, a patient
55:28
who presented with this had a T two hypotensive mass
55:31
and segmental fissure over here that enhances, um, you know,
55:34
modestly and is also FDG evidence.
55:36
So you'd call this carcinomatosis 10 times out of a 10,
55:40
except in this instance,
55:41
because we knew this patient had IgG four related disease.
55:45
So in that context, this may indeed end up being
55:47
IgG four related disease.
55:50
And, uh, we ended up treating this patient with steroids
55:52
with the IgG four related disease.
55:54
And look how small this, uh, this, uh, soft tissue got.
55:57
And so that, uh, shows us this is indeed was, um,
56:01
IgG four related disease involving the peritoneum.
56:05
Finally, I'll talk a little bit about lymph nodes.
56:07
Lymph node involvement is quite common,
56:09
so you're gonna see this, but, you know,
56:10
lymph node involvement, what does it really tell us?
56:12
Uh, not much, but just know that you can get, um, you know,
56:16
lymphadenopathy in patient with IgG four LA disease.
56:19
So don't have to be worried
56:20
that perhaps it's a manifestation of an underlying cancer.
56:23
There're typically though up to one
56:24
or two centimeters is no necrosis or calcifications.
56:27
And common sites you're gonna look at is actually in the
56:30
chest, the hilar region, the mediastinum axillary,
56:33
and then the neck area in the cervical area as well.
56:35
And interestingly enough, 80% of patients
56:37
with autoimmune pancreatitis, uh,
56:39
end up having hylo adenopathy.
56:40
And so they end up doing a CT scan of the chest
56:42
and you'll see these nodes.
56:44
Um, you know, that it's not an unexpected finding.
56:46
And case in point, we've seen this case
56:48
before in, in the, in the, in this, uh, in our slides
56:51
of autoimmune pancreatitis.
56:52
You go upstairs, uh,
56:53
they in fact ended up having adenopathy in the chest
56:55
that was indeed ftg avid.
56:57
But, you know, knowing
56:58
that this was all IgG four related disease,
57:00
this is not an unexpected finding.
57:03
So as we wrap up the session, these are the organ systems
57:06
that we've gone through a lot to remember.
57:08
But the three things I want you to focus on is the pancreas
57:10
with autoimmune pancreatitis, the biliary system
57:13
with a relatively long areas of wall thickening
57:15
and enhancement with, you know, not as much dilatation
57:18
of the upstream trees you would think about, uh, compared
57:21
to the degree of involvement.
57:22
And I think the retroperitoneum with RP fibrosis, um,
57:26
I think renal is also a good place to look.
57:27
I've seen increasingly patients with, uh, involvement in,
57:31
in one of these organ systems.
57:32
And I look at the kidneys, I see
57:33
what we call these pseudo tumors, um, that sort
57:35
of validates, uh,
57:36
and reaffirms my, my suspicion of IgG four A disease.
57:39
And I think it's important to also look at the vessels in
57:42
these patients because, you know, you wanna make sure that,
57:44
uh, the wall thickening is not causing stenosis, aneurysms,
57:48
dissections and things like that.
57:50
Don't be surprised if there's adenopathy.
57:52
And don't be surprised if in the context
57:54
of IgG four a disease,
57:56
you're seeing abnormalities in the prostate
57:58
and the peritoneum that look like cancer,
58:00
which just end up being but one
58:01
manifestation of that illness.
58:04
So in conclusion, IgG four L disease, um,
58:06
is an immune media disease.
58:08
It's a systemic disease.
58:09
It can, has issues everywhere,
58:11
but certainly in the abdomen and pelvis.
58:13
We're gonna focus on the pancreas, bile ducts
58:15
and the retroperitoneum.
58:17
I submit to you that in isolation this diagnosis can
58:19
be challenging to diagnose.
58:20
So the key thing here is
58:22
to look at all the organs, and that's what I do.
58:24
I mean, if I look at one of the organs
58:25
and I think, oh, could this be IG four related disease?
58:28
I look at other places and quite often I see disease
58:31
and other organs and that helps me go back
58:33
and, uh, suggest that diagnosis.
58:35
Uh, in my impression, you do need a biopsy, uh,
58:38
to help you make that diagnosis.
58:40
And again, the biopsy, the serum levels
58:41
and the imaging findings are all taken into context
58:44
to make that diagnosis.
58:45
And again, the reason we wanna make this diagnosis is
58:48
'cause there's great response to therapy therapy.
58:50
And so with that,
58:52
you can really make a huge impact for these patients' lives.
58:56
These are some references. And, um, back to our objectives.
59:00
We've talked about the pathophysiology.
59:02
We spent a lot of time looking at some imaging
59:04
manifestations and in the context of that,
59:06
looked at some disease mimics, um,
59:08
and compared in contrast, the imaging appearance of those.
59:11
And so with that, I thank you for your attention.
59:14
I know there's some questions and I'm happy
59:15
to start addressing them, uh, shortly.
59:20
Thank you so much, much for your lecture Dr.
59:21
Mather on I gg four diseases.
59:24
But yes, we'll accept questions now.
59:27
Please use the q and a feature, um, so we can answer
59:30
as many questions as we can before our time is up.
59:34
All right, so I, uh, will read some of the questions
59:36
that we've got in the chat at least.
59:38
Um, and starting from the top, first question I have is,
59:41
what are some clues on imaging
59:42
to differentiate focal autoimmune pancreatitis from chronic
59:45
focal pancreatitis?
59:47
Yeah, you know, I think with focal autoimmune pancreatitis,
59:51
um, as I said, you'll see more expansion of that portion
59:53
of the pancreas looks a little bit homogeneous,
59:55
and you're gonna hopefully see that duct kind
59:58
of poking its head through it and um,
60:00
and not see a lot of ductal dilatation upstream from it.
60:03
With chronic pancreatitis, usually, you know, the duct,
60:06
the pancreas itself is, is usually
60:08
a little bit more atrophied.
60:09
Um, you'll see some calcification associated
60:11
with chronic pancreatitis is one
60:12
of the classic things you'll see.
60:13
You'll see some duct irregularity
60:15
because of the chronic bounce of pancreatitis.
60:17
All of that is not something that is often, uh, is typical
60:20
of focal autoimmune pancreatitis.
60:23
Next question is steroids can cause pancreatitis.
60:26
Absolutely. Have you seen a case of autoimmune pancreatitis
60:28
treated with steroids
60:28
and then the patient gets certain his pan?
60:30
I have not seen a case of that I must submit to you,
60:32
to the patient who's, uh, to the, excuse me,
60:34
the my colleague who's asking, you know, you,
60:39
there are not a lot of cases of this going around
60:40
of autoimmune pancreatitis period.
60:42
Now I, uh, have had the benefit of perhaps, uh,
60:47
recognizing a few more of these because of my own interest
60:49
and recognize this disease.
60:50
But um, I think seeing a patient
60:53
who gets fewer use pancreatitis, you know, in the context
60:56
of autoimmune pancreatitis would be, um, quite fascinating
60:59
and perhaps something that somebody could write up.
61:01
I'm sure it's been reported though. Great question.
61:03
Is there a way of differentiating very subtle
61:05
retroperitoneal fibrosis from ineffective infective,
61:08
I'm sorry, stranding from early malignancy, the region
61:12
of the renal pelvis or ureter with pet CT help?
61:17
Um, renal pelvis and ureter?
61:21
Yeah, you know, I'm not sure if I
61:22
completely understand that.
61:24
I would say that, you know, pet CT doesn't always help
61:27
because active disease, I'll answer that portion.
61:30
Active disease of RP fibrosis,
61:31
particularly in the early stage can be pet positive
61:34
malignancy can be pet positive malignancy can be pet
61:36
negative and so can can RP fibrosis.
61:38
So pet CT is not always as helpful as we would like.
61:41
Um, listen, if I'm just seeing stranding in the
61:43
retroperitoneum, it's not enough for me
61:45
to call retroperitoneum fibrosis.
61:47
It may be early RP fibrosis,
61:48
but you know, I, I think it's gonna be hard for me to make
61:51
that definitive diagnosis based on stranding, you know,
61:54
RP fibrosis, just really as I said, you know, sheetlike,
61:57
you know, tissue that is surrounding the aorta and um, and,
62:01
and, and and the ant lateral aspects of it.
62:04
Um, if I'm just seeing stranding there, yes,
62:06
maybe it may grow to be RP fibrosis
62:08
but I don't think many people are gonna
62:09
be calling that prospectively.
62:10
And um, and I think that's okay.
62:13
You know, if you're gonna call stranding
62:14
and the retro period seems subtle stranding RP fibrosis
62:16
or potentially RP fibrosis every time
62:19
you know you're gonna be wrong most of the times.
62:21
'cause remember all these diseases are rare
62:23
and stranding can be there for a variety
62:24
of reasons that may come and go.
62:27
The next question are any specific indications
62:29
or contraindications for prostate cancer?
62:33
Well, I'm so sorry. I don't know
62:34
if I understand that question.
62:36
Um, so I'm going to respectfully
62:41
go on to the next one.
62:42
If that attendee wants to reframe that question,
62:45
I'm happy to answer it.
62:47
Uh, I will say that
62:49
if the question is indications we're getting imaging
62:52
of the prostate and IgG four related disease.
62:55
That specific case I showed was a patient
62:57
who had IG four related disease
62:59
that ended up having some urinary symptoms.
63:01
They did a PSA level that was elevated,
63:03
which is why they got the, uh, the prostate.
63:05
Mr. Uh, next question of have you ever seen a case
63:08
of intracranial IG four related vasculitis?
63:11
Uh, I'll say that I have not seen a case of that.
63:14
That said, my focus is entirely an abdomen pelvis.
63:19
And so, um, I'm sure there are cases out there, uh,
63:22
but I have not had the privilege of of seeing them, uh, yet.
63:27
So let's see. Next question is, do so most
63:29
of these patients, so, so do most
63:31
of the patients need a biopsy
63:33
for definitive focal pancreatic finding amyloid?
63:35
A differential renal findings is diffusion top.
63:37
Okay, so three questions here. Yes.
63:39
So, um, to make a definitive diagnosis,
63:41
you need a biopsy right now, it's ironic that I say that
63:45
because even on biopsy sometimes you
63:46
can't get a definitive diagnosis.
63:48
So the key thing I think I want to impress upon, uh,
63:51
everyone here is that there's sort of three aspects, three
63:53
to four aspects of making this diagnosis, right?
63:56
There's the radiology aspect
63:57
that can be quite classic for the disease.
64:01
There is the biopsy that again,
64:03
can support the radiological diagnosis.
64:05
There is serum levels that can support it.
64:07
Then there's a clinical picture as well.
64:09
And so I think once you have all four of those,
64:13
you know, in context, uh, allows you
64:15
to again, make that diagnosis.
64:17
But the biopsy certainly helps and it's a part of that.
64:19
Um, amyloid A is amyloid has a
64:22
differential for the renal findings.
64:24
You know, uh, I don't know if I've seen a case
64:28
of renal amyloid to be honest.
64:30
I think if it's there, it must be quite, quite rare.
64:32
I've seen maybe a case of amyloid in the retroperitoneum.
64:36
Um, I think for my renal findings, uh, the one, the couple
64:40
of pitfalls that I put in there, um, uh,
64:45
including, you know, pilo, you know, maybe lymphoma,
64:47
maybe mets the things that I think can realistically mimic
64:50
it and that are common enough to mimic it.
64:52
But if you see the renal findings in the context of pancreas
64:56
or biliary or retroperitoneal
64:57
or vascular issues, um, I certainly put in the report, yeah,
65:00
I see these internal renal findings,
65:01
but guess what, it can be seen with IG four related disease
65:04
diffusion weighted imaging.
65:06
I gotta tell you, I I'm not, um,
65:08
I don't remember the literature on this,
65:10
but I don't, it, it doesn't really help.
65:12
Um, you know, you're gonna see restricted diffusion, uh,
65:16
with anything that, that,
65:17
that doesn't allow water molecules to dissipate.
65:20
Um, just certainly, you know, you'll see that
65:23
with autoimmune pancreatitis to a certain degree.
65:25
You'll probably see that with cancers.
65:27
Um, you know, you may see that with some forms
65:29
of pancreatitis as well.
65:30
So I don't find that that's been as useful.
65:32
I think just the way it looks like, I think
65:35
that mass like enlargement the sausage shape, the rind
65:38
of signal that's surrounding the pancreas,
65:40
those three things I think and,
65:42
and also what it does to the doctor, those are,
65:43
are the things that are most helpful to me.
65:46
And we have one last question that I see here,
65:47
and I'll go to the chat, see there anymore is involving
65:49
steroid causing further damage before I diagnosed findings.
65:51
So is there any way if you can suggest, um,
65:57
while performing for diagnosis, oh,
65:59
I'm not sure if I understand that question.
66:00
Is involving a steroid co
66:03
steroid cause further damage while performing
66:06
for diagnosis for findings?
66:11
I mean, I, I'm not sure if I understand the question.
66:12
Maybe, uh, I, I apologize,
66:14
but I will say that um, you know, we, you know,
66:18
the idea is always is to make the diagnosis
66:20
before initiating therapy.
66:22
And so, um, you know,
66:24
certainly there are downsides to using steroids.
66:27
Um, so you're not gonna just start it on a patient if you're
66:29
not sure that's what you're dealing with.
66:30
So it's important to sort of take the time
66:32
to make the diagnosis and then, uh, initiating steroids.
66:35
And again, if they're contraindication to steroids,
66:37
there are second line treatments that one can use.
66:41
Um, wonderful.
66:43
So those are the questions I will look at the chat.
66:47
The thyroid manifestations is somebody is
66:50
asking, I'd have to look back.
66:52
I think there's certain types of thyroiditis
66:55
that can, can do it.
66:56
Let me just look at the slides.
66:58
I don't have that information off the top of my head,
67:01
but I will look at the slides right now.
67:04
'cause it had that ma the big slide
67:05
in all the manifestations.
67:07
I think it was types of, um, uh, bridal thyroid.
67:11
This that's what I thought. Yeah, so, so it's thought that,
67:14
uh, you know, different types of, some different types
67:16
of thyroiditis may be manifestations
67:17
of IgG four related disease.
67:21
Perfect. I think that is just all the questions
67:25
that we have for the moment.
67:26
And so if that's it, I'd like to thank, uh,
67:28
modality again for hosting.
67:30
And most importantly, I'd like to thank the audience.
67:33
I'm always humbled by, uh,
67:34
how many people join these seminars
67:35
and engage with, uh, the content.
67:39
Um, I'm always happy to, you know,
67:41
take things offline as well.
67:43
I think I have my email and Twitter account
67:45
or X account over there
67:46
and I'm certainly happy
67:47
to engage with the audience that matter.
67:48
So thank you everybody. Thank
67:50
You so much Dr. Mather
67:51
for sharing your expertise with us
67:53
and answering questions.
67:54
And thank you for everyone participating in our noon
67:57
conference today and asking great questions.
67:59
You can access the recording of today's conference
68:02
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68:03
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68:05
We'll also email out a link to the replay later today.
68:09
Be sure to join us next week on Thursday,
68:12
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68:14
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68:17
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68:20
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68:26
Thanks again and have a great day.
Mahan Mathur, MD
Associate Professor of Radiology & Biomedical Imaging, Vice-Chair of Education & Director of Medical Student Education in Radiology
Yale School of Medicine
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