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Hello and welcome to Noon Conferences hosted by MRI Online.

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3 00:00:07,320 --> 00:00:08,880 In response to the changes happening around

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the world right now and the shutting down of

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in-person events, we have decided to provide free

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Noon Conferences to all radiologists worldwide.

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Today we are joined by Dr. Nanda Thimmappa.

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Dr. Thimmappa is Medical Director of Ultrasound,

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Radiology Residency Associate Program

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Director and Assistant Professor of Radiology

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at the University of Missouri-Columbia.

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Her research interests include evaluation

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of MR technology and MR contrast efficacy,

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and contrast-enhanced ultrasound.

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A reminder that there will be a Q and A session

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at the end of the lecture, so please use the

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Q and A feature to ask your questions, and we will

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get to as many as we can before our time is up.

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Also, we will be using the polling feature today.

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So just a quick reminder to let everybody know that

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the window that appears for the polling feature can

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be moved around your screen if it is blocking images.

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That being said, thank you all

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for joining us today. Dr. Thimmappa,

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I'll let you take it from here.

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All right.

1:08

Um, good afternoon, uh, to my East Coast

1:12

colleagues and good morning, uh, to,

1:15

uh, and good evening wherever you are.

1:18

Um, um, uh, thanks again, Ryan,

1:21

for that nice introduction.

1:22

And today I will be talking

1:25

about, uh, imaging of the spleen.

1:28

I do not have any

1:30

relevant financial disclosures.

1:32

I would, um, like to thank my colleagues at the

1:35

University of Missouri, which is in Columbia,

1:38

which is a college town between Kansas City and St.

1:40

Louis.

1:40

Um, thank you to all my colleagues for,

1:43

uh, sharing their best cases for this talk.

1:47

Today we will discuss about, um, the normal

1:51

appearance of the spleen and, uh, this will be a

1:54

case-based learning of various clinicopathologies.

1:57

Obviously, the splenic pathologies are wide,

2:00

and it'll be beyond the scope of this, uh,

2:03

one-hour lecture to cover each one of them.

2:06

Uh, but I've tried my best to, uh, bring the most

2:10

common pathologies and also some of the uncommon ones.

2:14

Um, but with specific imaging, uh, features,

2:18

uh, to help us characterize these lesions.

2:20

And most importantly, we'll discuss a

2:22

bit about management of these lesions.

2:27

Now, uh, the spleen is an intraperitoneal

2:30

organ in the left upper quadrant of the body.

2:33

Um, we will not speak in detail about the

2:37

histological features, but there are two important

2:39

parts or components of the spleen we should know:

2:43

the white pulp and the red pulp. The red pulp—

2:47

um, the white pulp is the lymphoid

2:49

tissue around the splenic vessels, and

2:52

this enhances almost immediately after

2:55

the contrast reaches the central, uh, arterial

2:58

vasculature of the spleen, and the red pulp,

3:02

which is mainly made up of venous sinusoids,

3:05

enhances a bit later.

3:07

And that's why we have this heteroirregular

3:11

pattern of enhancement of the spleen.

3:13

And there is really a lot of

3:15

variability, um, of enhancement pattern.

3:19

It's called zebra appearance.

3:21

Um, and also, uh, an interesting point to note

3:25

is that, uh, with age the white pulp becomes

3:29

bigger, it hypertrophies, and, um, so, um, kind of

3:35

the heterogeneous enhancement can also

3:38

change with age, and this pattern of enhancement

3:42

is seen only in the arterial phase, and it

3:45

becomes homogeneous almost immediately, uh,

3:48

within 10 to 15 seconds post-injection.

3:52

And sometimes if the arterial phase is delayed,

3:54

we may not even, we may not even catch this.

3:57

Uh, these are the CT images, a

3:59

non-contrast appearance of the spleen.

4:01

It's usually homogeneous.

4:04

And, uh, uh, of density, usually between

4:06

30 to 40, uh, soft tissue densities range.

4:11

And, um, again, we see this zebra,

4:14

uh, zebra or, um, kind of, um, arch.

4:17

It's called various names: archiform,

4:20

or heterogeneous enhancement in arterial phase.

4:24

Blends in and becomes homogeneous in venous phase.

4:28

And again, the enhancement starts to

4:31

decrease, uh, in delayed phase.

4:35

Similar appearance on MR. And,

4:38

uh, with MRI, um, uh, we kind of—

4:43

MRI is usually almost always multiphasic.

4:45

So we do see all these phases. On CT,

4:48

we usually obtain venous phase imaging, so

4:51

we may not see the heterogeneous enhancement.

4:54

Now, I emphasize on this because it is

4:56

important to realize that, um, the red pulp

4:59

and white pulp dynamics can give this

5:03

variation in appearance, uh, which, and it's

5:06

important to differentiate this from lesions.

5:09

Now, diffusion of the spleen.

5:11

Diffusion is my most favorite sequence in MRI.

5:14

Um, it helps us characterize a lot of abnormalities

5:17

in body imaging. With spleen though, uh, the spleen

5:21

is intrinsically bright on diffusion-weighted

5:26

images, and it's dark on ADC, so sometimes it's

5:29

kind of really hard to, um, see lesions, which

5:34

also may restrict.

5:35

However, because the spleen itself is bright,

5:37

it helps us localize the lesions which are

5:40

subtle and not seen in other sequences.

5:43

Um, and also, uh, in this case, this—this is a

5:46

case of diffuse myeloma, and we were able to actually

5:50

see the lesion on diffusion-weighted images.

5:53

There is also involvement of the liver.

5:54

As you can see now, a diffusion-weighted—there is.

5:58

A few publications about diffusion-weighted images

6:01

of the spleen, but I—I do think, uh, this is one

6:05

of those areas which can utilize more research.

6:08

Um, and there have been reports of how the ADC

6:12

values change with improvement in cirrhosis.

6:17

And, um, I do like, uh, using the diffusion image to

6:21

actually localize the splenic tissue when in doubt.

6:24

For example, in this patient who had splenectomy,

6:27

there was some residual splenic tissue in the

6:29

splenic bed, which did restrict avidly, and, uh,

6:34

which helped us confirm that this was indeed spleen.

6:40

And on ultrasound, the spleen is homogeneous.

6:43

And, um, really, um, it is—ultrasound is an excellent

6:48

modality to look for especially cystic lesions.

6:51

There is, uh, no radiation involved.

6:54

Um, so if there are any

6:57

hyperdense lesions on MRI which, uh, on

7:00

CT, which kind of overall look benign—

7:03

uh, then ultrasound could be the next modality.

7:06

It helps us localize the lesions,

7:08

especially hypoechoic cystic lesions.

7:11

And also it is a great modality for follow-up

7:13

of hematomas, infarctions, or abscesses.

7:19

Now, contrast-enhanced ultrasound of the spleen.

7:21

I have not done a single case for the

7:24

spleen, but in this example, uh, this—

7:28

images were obtained for evaluation of

7:30

this lesion in the inferior pole of the kidney,

7:34

and we had a lot of spleen in our field of

7:36

view, so I thought I'd share it with you guys.

7:42

And, uh, there is an initial delay for the

7:44

contrast arrival to the spleen, and all

7:47

these tiny microbubbles are potent reflectors

7:50

of the ultrasound beam, and you see them.

7:52

Then I think you may have noticed that,

7:54

initially, similar to the CT and MR images,

7:57

there was enhancement of the white pulp followed

8:00

immediately by the enhancement of the red pulp

8:03

and eventual homogeneous enhancement of the spleen.

8:06

Um, I think there is a huge potential for growth of

8:10

contrast-enhanced ultrasound of the spleen at this—

8:13

uh, it is a safer modality, especially

8:16

in patients with renal failure.

8:18

Um, also, there is no radiation involved, so this

8:21

could potentially become one of the modalities

8:23

for evaluation of these clinic lesions.

8:25

It's not extensively studied at this point, but I

8:28

would definitely like to use this in the future.

8:33

And, um, for the sake of completion,

8:36

um, the nuclear medicine studies, uh,

8:39

performed for the spleen are limited.

8:41

The most common modality that is used

8:43

is a Technetium-99 sulfur colloid study.

8:46

Um, the sulfur colloid is picked up by the

8:49

reticuloendothelial cells of the body.

8:52

And, um, any tissue which contains reticuloendothelial

8:55

cells is seen, for example, in this—

8:58

patients with splenectomy.

8:59

There was this focus within the splenic bed,

9:02

which did pick up the, uh, tracer, and, um,

9:05

um, so this was a case of splenule or splenunculus

9:09

tissue in the splenic bed. Splenic size—

9:13

again, the range described as 9 to 13 centimeters.

9:18

Are always better, and also because of the way the

9:22

spleen is placed in the left upper quadrant, uh,

9:25

there is no good plane for measurement of value.

9:28

Optimum measurement of, um, the splenic size.

9:32

I usually perform—obtain a

9:34

craniocaudal, um, dimension.

9:37

Um, uh, measure the size along

9:39

the craniocaudal dimension.

9:41

But sometimes, if the spleen is more horizontally

9:43

oriented, you could obtain an anteroposterior

9:46

measurement, uh, for the spleen.

9:49

Now, this number 13 centimeters is, um, kind of

9:53

an average splenic size.

9:55

Uh, but also you should look for the patient build.

9:58

Sometimes the splenic size

9:59

depends on patient body habitus.

10:02

In really tall individuals, they will have, um,

10:06

concomitantly larger splenic and, um, liver sizes,

10:10

which may be normal for their body habitus.

10:13

Uh, so it is important to keep all

10:15

those factors in mind, and also—

10:18

uh, the causes for splenomegaly.

10:20

There are several causes, right?

10:22

Um, most commonly, uh, which we see in our practices,

10:26

uh, from congestion, from portal hypertension. It can

10:30

also be seen with infections, lymphoproliferative

10:32

disorders, metabolic disorders, um, and malignancies.

10:38

Okay.

10:39

Let's see some cases.

10:40

This is case one.

10:41

Question one: what is the diagnosis?

10:48

All right, very good.

10:49

Um, so majority of you are right. There

10:53

are multiple soft tissue structures in

10:57

the left upper quadrant, well-rounded.

10:59

They're large in size.

11:00

They're not tiny like the small

11:02

spleens that we just discussed.

11:04

So this is indeed polysplenia.

11:07

Now, um, you have to remember that, um, polysplenia,

11:13

and, uh, splenules and accessory splenules—

11:16

these are all, um, these are all

11:19

developmental anomalies of the spleen.

11:22

Um, there is no significance to this.

11:25

Uh, we just have to make sure we do not

11:26

confuse this with masses or other abnormality.

11:30

Uh, polysplenia is when various—

11:32

uh, mesenchymal cells or, um, the splenic components

11:37

do not fuse, so they are seen as individual components.

11:41

This is congenital.

11:43

Um, splenule is when one of the components

11:46

doesn't fuse with the rest of the spleen.

11:48

And, um—

11:50

uh, you can also have, uh, splenic

11:53

clefts when it has not fused completely.

11:55

And splenosis is acquired.

12:01

This is seen post-trauma, uh, when, uh, major—

12:05

either when the spleen just gets fragmented and

12:08

they're not able to remove all, or it gets ruptured

12:11

and they're not able to remove all components.

12:13

Then splenosis can be seen elsewhere

12:16

in the peritoneal cavity.

12:18

And if there is

12:19

rupture of the diaphragm,

12:20

it can also be seen in the thoracic cavity, as in

12:23

this case there was trauma to the diaphragm,

12:26

and there was splenic tissue, um, in the

12:29

thoracic cavity adjacent to the diaphragm.

12:32

Um, this is, um, another example of splenosis.

12:37

Uh, in this case there was a mass in the

12:40

pelvis in a male patient, and there are

12:43

kind of not a lot of differentials for solid

12:45

masses in the pelvis in a male patient.

12:48

Um, on looking at the, uh, rest of the images—um,

12:54

so these are CT images.

12:56

I'm scrolling from pelvis

12:58

superiorly to the upper abdomen.

13:05

In the left upper quadrant, you see a metallic clip.

13:07

So this patient's spleen was removed, and, uh, some of

13:11

the fragments ended up in the pelvis and they grew.

13:14

And this was another nice example

13:16

of splenosis in the pelvis.

13:19

Okay, question number two.

13:22

What is the diagnosis?

13:25

We are discussing about spleen today.

13:27

So the abnormality that you see—is this a

13:30

retroperitoneal mass, sliver of the liver, wandering

13:34

spleen, or is this cell lymphoma? Great. Again,

13:40

majority of you are right.

13:42

Um, so this is indeed

13:46

suspicious for wandering spleen.

13:48

The spleen is not seen in its usual location

13:51

in the left posterior upper abdomen.

13:55

Uh, but instead it is kind of seen more,

13:58

uh, anteriorly, and the pedicle and the

14:01

splenic hilum are facing more posteriorly.

14:04

Uh, this is a malpositioned

14:06

spleen, and, uh, the etiology is because of laxity of

14:12

all the ligaments which hold the spleen in place.

14:16

It can also be because of congenital deficiencies

14:19

of these ligaments, which could be the

14:21

gastrosplenic, phrenicosplenic, or

14:25

splenorenal ligaments.

14:27

These are the ligaments which keep the spleen

14:29

in position in the left posterior upper abdomen.

14:32

And when these ligaments are either elongated

14:35

or become lax, either during pregnancy,

14:38

or because of splenomegaly, um, or if

14:41

they're deficient congenitally, we do

14:43

come across a classical wandering spleen.

14:46

In this case, it is in the left upper abdomen still,

14:49

uh, but it could be in the pelvis,

14:51

it could be anywhere in the—

14:52

abdomen, and there is a risk of torsion

14:56

uh, with the wandering spleen.

14:58

So this should be, um, kept an eye on.

15:03

The splenic pathologies are again wide, and

15:05

we are just, uh, discussing important cases.

15:08

Uh, I would mainly divide this into

15:08

Uh, I would mainly divide this into

15:11

pathology secondary to trauma, trauma

15:13

or vascular involvement, infections,

15:16

splenomegaly, and various masses.

15:18

We'll be looking at some of those

15:20

splenic masses now, because the pathology—

15:23

there is such a wide variety.

15:26

Uh, it's important for us to differentiate

15:29

which one is benign and which one is malignant.

15:32

And, um, also, what do we do about these incidental

15:35

splenic masses? Thankfully, um, we do have, um—

15:41

ACR guidelines, and I also wanted to bring up a point

15:43

that, um, the malignant lesions within the spleen are

15:47

incredibly low.

15:49

In fact, in this article they say that,

15:51

um, only 1% of these masses that are

15:54

abnormalities seen are, in fact, malignant.

15:57

And it's important for us to just look at them.

15:59

And imaging plays a huge role in

16:02

um, characterizing these masses.

16:06

So, and this is the incidental, uh, workflow

16:11

algorithm suggested by, uh, the ACR, by the ACR

16:15

Incidental Findings Committee on splenic findings.

16:18

And, uh, basically they say that if the imaging

16:22

findings are diagnostic and it's benign, we

16:24

really do not need any further follow-up. If the

16:27

imaging features are not diagnostic—

16:29

stick.

16:30

However, if you do have prior imaging and it is

16:32

stable, then there is no need for any further imaging.

16:36

If it is not stable, then we need to evaluate it,

16:39

um, usually by another modality, or sometimes by

16:43

another imaging modality, or sometimes by biopsy.

16:46

If there is no prior imaging,

16:49

and if there is history of cancer,

16:51

there is a concern for metastasis.

16:53

Uh, usually these metastatic lesions

16:56

are more than one centimeter.

16:57

They do show growth over time, and it is important to

17:01

evaluate those lesions or see if the metastatic lesion

17:05

looks similar to the primary lesions. If there is no

17:08

history of cancer, if there are suspicious imaging

17:11

features, which I'll discuss in the next few slides,

17:14

you have to evaluate them further.

17:16

And if there are indeterminate imaging

17:18

findings, then follow-up is, um, necessary.

17:22

And again, uh, I really like this

17:25

algorithm proposed by this article.

17:27

Um, and, uh, because even if you do think

17:31

the masses are benign, sometimes they can

17:34

be symptomatic, and that is when splenectomy or

17:38

partial splenectomy or splenic artery embolization

17:41

may be necessary. They can be symptomatic

17:44

just by their size, uh, or they can be

17:47

symptomatic by systemic manifestations.

17:51

Some of these masses can cause thrombocytopenia,

17:54

so the management should depend.

17:56

Uh, it should be case-to-case basis and should

17:58

depend on the patient's symptoms as well.

18:02

Okay.

18:02

Let's look at case three.

18:05

So the question three is: what is your diagnosis?

18:09

Are these, uh, structures—

18:12

indicated by the A arrow,

18:14

are these splenic granulomas?

18:16

Are these Gamna-Gandy bodies?

18:18

Could this be seen in Wilson’s disease?

18:21

Are these splenic microabscesses?

18:24

Great.

18:24

Um—

18:25

but this is, this is a nice distribution of

18:28

Gamna-Gandy bodies, um, and splenic granulomas.

18:33

Now, they both can look like this.

18:36

Um, I specifically didn't tell you what imaging

18:39

modality it is, because one of the

18:41

steps of figuring out the answer to this

18:44

question is seeing which sequence this is.

18:47

So you do see nice India ink

18:50

lining around the spleen here.

18:51

So this is out-of-phase imaging, and this is in-

18:55

phase imaging, and these structures which are

18:59

pointed by the A—they're really seen

19:02

well on in-phase imaging and not seen that well

19:04

on out-of-phase imaging, which indicates that these

19:08

tiny little structures contain iron in them,

19:12

and there was signal dropout on in-phase images.

19:15

They were not seen that well on T2-

19:17

weighted image, and they were seen on these

19:20

post-contrast images or T1-weighted image.

19:24

This is a gradient-echo image, and, uh, you

19:26

could see susceptibility artifacts with

19:28

structures that contain iron or calcium.

19:31

So you'll see them on this sequence.

19:33

So the correct answer is Gamna-Gandy bodies.

19:36

And now, how do we differentiate

19:38

these from granulomas on MRI?

19:41

Because on CT you see granulomas as calcified

19:45

foci, and it's so common and, you know,

19:48

it's especially in a few endemic areas—

19:52

it is so common that we can see them on CT.

19:54

On the MR though, calcification is intensely

20:00

hypointense, both on T1- and T2-weighted images.

20:03

So you'll see that both on out-of-phase and in-phase

20:06

images. You'll also see them on T2-weighted

20:09

images in this T2 HASTE, and on, uh, T1-

20:13

weighted images as well. They do not enhance.

20:16

So that's how we differentiate

20:18

granulomas from Gamna-Gandy bodies.

20:23

Okay.

20:23

Question four.

20:25

What is the diagnosis for this structure

20:29

along the medial pole of the

20:32

spleen, or medial aspect of the spleen?

20:36

This is T2-weighted image, T1 pre-

20:40

contrast, arterial phase, and delayed phase.

20:45

Great.

20:46

There is a good, uh, split between, um,

20:49

lymphangioma and hemangioma for good reason.

20:52

Um, this is a case of splenic lymphangioma, uh,

20:58

but sometimes it's kind of hard to differentiate.

21:01

Um, so a good rule is that—

21:05

lymphangiomas do not show much enhancement.

21:09

They are mainly cystic.

21:10

They're very bright and cystic compared to

21:14

hemangiomas, and, um, they're intensely T2 bright.

21:18

Uh, they may have some hemorrhagic components

21:21

in them, uh, for example, in this T1-

21:24

um,

21:25

pre-contrast image.

21:27

It is even bright.

21:28

Uh, it did show a little bit

21:30

of enhancement of this patient.

21:32

Uh, so this is a splenic hemangioma.

21:35

And, uh, cystic masses of the spleen.

21:38

Splenic hemangiomas are one of them, but

21:40

there could also be splenic cysts, which is

21:42

an epidermoid cyst lined by an epithelium.

21:45

And they say the—

21:46

splenic cyst itself is formed, uh, when these splenic

21:50

components fuse and the peritoneum gets invaginated

21:54

between these components, and that's kind of,

21:57

uh, leads to the formation of a splenic cyst.

22:01

Uh, there are parasitic cysts such as hydatid cysts,

22:04

and pseudocysts that can develop either secondary

22:07

to hematoma, infarction, or necrosis from pancreatitis.

22:13

Let's look at some solid masses.

22:15

Again, there are a lot of splenic masses,

22:17

and I don't know why it's called a forgotten

22:19

organ, because it has such wide pathology.

22:22

Uh, some of the important ones are benign masses,

22:25

such as hemangioma, hematoma, sclerosing angioma,

22:29

nodule transformation, also called SANT.

22:32

Um, and there are some with intermediate potential.

22:36

Some of these could potentially become malignant,

22:39

such as littoral cell tumors, which are angiomas,

22:42

and hemangioendotheliomas. Malignant masses:

22:45

cell lymphoma, angiosarcoma, and metastasis.

22:47

Let's see some of these lesions as cases.

22:51

Uh, this is question five.

22:53

Um—

22:54

next case: a 21-year-old male presenting

22:57

to the emergency department, uh,

22:59

with CT performed for abdominal pain.

23:01

There is a hypodense mass within the, uh,

23:06

spleen, and, um, following this algorithm,

23:10

this kind of had intermediate features.

23:13

So I think further follow-up was

23:15

performed, and, um, this mass was

23:20

uh, kind of isointense to spleen on MRI.

23:24

And, um, it shows, um, these features on post-

23:28

contrast images and these features on ultrasound.

23:32

So let's put up question five now.

23:34

What is your diagnosis based on, um, imaging findings?

23:39

Is this a splenic lymphangioma?

23:42

Is this splenic hemangioma, lymphoma, or a hematoma?

23:47

That's great.

23:48

Um, so majority of you answered splenic

23:52

hemangioma. That is the correct answer.

23:55

Um, hemangiomas are bright, they're

23:58

echogenic on ultrasound images, and this

24:01

mass was echogenic without much vascularity.

24:05

It was hypodense with some

24:07

internal enhancement on CT images.

24:10

It kind of showed this, um, you know,

24:12

peripheral enhancement with central fill-in.

24:16

And, uh, the delayed fill-in is one of

24:19

the features of hemangiomas of the spleen.

24:23

Uh, the hemangiomas in the liver, especially

24:26

the cavernous hemangiomas, show typical discontinuous,

24:30

nodular, peripheral enhancement. That's not

24:34

classically, almost always, seen with hemangiomas

24:37

in the spleen.

24:39

Uh, but you do get some of the nodular enhancement,

24:42

and there are occasional cases when you can, uh, see

24:45

this discontinuous enhancement in the, um, spleen.

24:51

On MR again shows similar features to CT.

24:55

There is delayed fill-in.

24:56

It is T2 bright.

24:58

It has that intermediate T2 brightness, which you

25:00

see with hemangiomas, and that's the benefit of, uh,

25:04

MRI where you—the T2 on the T2-weighted images.

25:06

You kind of, um, can confidently

25:08

call this, uh, a hemangioma.

25:12

And, uh, this is the most common primary

25:14

neoplasm of the spleen, usually asymptomatic.

25:18

It, it can be associated with a few syndromes and, uh,

25:21

it's benign and no further follow-up is necessary.

25:25

Uh, let's look at the next case.

25:27

This is a 52-year-old male

25:29

with left upper quadrant pain.

25:31

You see this mass, which is

25:33

bulging the capsule of the spleen.

25:36

There may be some vessels within this mass.

25:40

And on the CT it's isointense to the, um, spleen.

25:46

And on, um, MRI, it does show some enhancement, but

25:52

it kind of becomes more homogenous to the spleen.

25:55

So based on these imaging

25:57

findings, what is your diagnosis?

26:01

So is this a splenic hematoma?

26:03

Is it a hemangioma, like the case

26:05

we just discussed prior to this?

26:07

Could this be a lymphoma or a hematoma?

26:12

Perfect.

26:13

Majority of you answered splenic hematoma.

26:15

That is correct.

26:17

Um, so compared to—

26:20

the hemangioma, just that we just saw,

26:23

this is more hypoechoic.

26:25

It could also be heterogeneous.

26:27

It can have these vessels coursing through it.

26:30

Um—

26:31

with, it's kind of really nonspecific on CT

26:34

and MRI, uh, it causes contour abnormality.

26:38

It is slightly more bright than hemangioma,

26:42

but then again, it is really nonspecific.

26:45

Um, it can, it can be really hard to differentiate

26:48

this from, uh, uh, hemangioma and sometimes both.

26:52

Uh—

26:53

diagnoses are given as differentials,

26:56

and fortunately both of them are benign,

26:58

and no further treatment is required.

27:00

Um, so, uh, I do think ultrasound and

27:04

brightness on T2 can be good pointers

27:07

to calling this hematoma over hemangioma.

27:11

This hematoma is also associated with a few syndromes.

27:16

Okay, let's look at the next case.

27:17

Uh, this is a 21-year-old female

27:19

presenting with headache and fatigue.

27:21

Her platelet count was low, and, um, this

27:25

is, um, the spleen, which was enlarged.

27:30

And on MRI, you see these findings.

27:34

Um, this is a T2-weighted image, and these are

27:38

pre- and post-contrast, uh, T1-weighted images.

27:43

What is your diagnosis based on these imaging findings?

27:47

Very good.

27:48

Uh, looks like the audience really knows

27:50

their spleen stuff. So this is indeed SANT.

27:56

And, um, the Sclerosing

27:58

Angiomatoid Nodular Transformation.

28:00

Um, it's kind of a long name, so

28:02

thankfully it has an abbreviation: SANT.

28:05

Uh, so this is sometimes called cord capillary

28:09

hemangioma or multinodular hemangioma.

28:10

In this patient, this mass was removed.

28:14

Um, so, it's—

28:16

technically benign, but it can cause symptoms.

28:20

So, um, kind of, uh, going back to that algorithm

28:23

that we discussed, even if the lesion's benign,

28:26

if it's causing symptoms just because of its size

28:30

or because of destruction of platelets or other

28:32

systemic effects, then spleen may have to be removed.

28:36

Um, it is an abnormal stromal response to splenic

28:40

insult, with nodular transformation of the vascular

28:42

uh—

28:44

bed.

28:44

Uh, it can, it can have three distinct

28:46

types of, uh, small blood vessels:

28:48

capillaries, sinusoids, and small veins.

28:51

And, um, the differential, you

28:53

kind of includes malignancy.

28:55

It does have—it's intensely

28:57

dark on MRI. On ultrasound,

29:00

it's variable.

29:01

Um, it does demonstrate internal vascularity.

29:05

Um, and also, um—

29:08

on MRI it can be hyperintense on

29:11

T2. It's heterogeneous to hyperintense

29:14

on T1. It has this spoke-wheel enhancement

29:17

with hypoenhancing central scar.

29:19

It can have iron in it, and that's why

29:22

it's, uh, dark on, uh, gradient-

29:25

echo images and also on in-phase images.

29:30

Next case.

29:32

This is a 69-year-old female with chronic

29:34

abdominal pain, anemia, thrombocytopenia.

29:37

She also had fever, chills, weakness, fatigue, and

29:40

then abdomen CT was performed to look for etiology

29:44

of her chronic abdominal pain and thrombocytopenia.

29:47

Uh, and of course we, uh, paid

29:49

specific attention to the

29:51

spleen, uh, because spleen can destroy.

29:54

Platelets and other, uh, blood cells, uh, which could

29:57

be the etiology for thrombocytopenia in this case.

30:01

The spleen itself was not enlarged significantly, but

30:04

there was a hypodense mass along its anterior aspect.

30:08

And, uh, patient did have a

30:10

CT from a year and a half ago.

30:12

There was no lesion in the spleen at that point.

30:16

Um.

30:17

So this grew in the last year and a half.

30:20

Uh, we did do an MRI because

30:22

this is an indeterminate mass.

30:24

Uh, this is coronal, contrast-focused

30:26

images of the coronal images.

30:28

It's hyperdense.

30:30

It was really dark on pre-

30:32

contrast T1-weighted images.

30:34

It did enhance on post-contrast

30:37

MR. So based on this, um, uh, on

30:42

the images, what is your diagnosis?

30:47

Now, kind of, uh, full points to anybody

30:50

who attempts to attempt the question.

30:53

Uh, just, um, do your best guess.

30:55

Is this lymphoma, littoral cell tumor,

30:58

angiosarcoma, or metastasis?

31:00

Again, with splenic masses, some of the

31:02

findings are nonspecific and, uh, it just—

31:06

clinical picture helps us come to the diagnosis.

31:12

There was a nice split between lymphoma

31:15

and littoral cell tumor, with slightly

31:18

more votes for, uh, littoral cell tumor.

31:21

And again, you're absolutely right.

31:23

Uh, this is littoral cell tumor on CT.

31:27

This is a hyperattenuating nodule.

31:30

It can grow, um, not very rapidly, but

31:34

relatively faster, uh, compared to some

31:36

of the other splenic lesions. On MRI,

31:39

the imaging appearance could be variable.

31:42

Uh, it could be hypointense on, uh, gradient-

31:45

echo post-contrast images, uh, because

31:48

of hemosiderin and, um, um, it can enhance.

31:53

Um, so the, in this case, um—

31:57

the patient had her spleen removed,

31:59

and that's why we know the diagnosis.

32:02

Um, the littoral cell tumor can be

32:03

angio- or hemangioendotheliomas.

32:06

Uh, the hemangioendotheliomas have

32:09

solid areas with foci of necrosis and, um—

32:13

there could be, they are more likely

32:16

to be symptomatic. In this patient,

32:17

um, she had all these symptoms of, uh, chronic—

32:21

she had, including, she had chronic pain.

32:24

And, uh, there is malignant potential.

32:26

So this, uh, once there is a suspicion

32:29

for a littoral cell tumor,

32:30

this, uh, spleen is removed.

32:33

Let's look at the next case.

32:35

Um.

32:36

This is a 70-year-old woman with, uh, a newly

32:39

diagnosed cervical cancer, and she had a PET-CT

32:44

performed for staging, and there is a splenic lesion.

32:50

And based on these imaging

32:51

findings, what is your diagnosis?

32:53

Is this cell lymphoma, hematoma, angiosarcoma, or—

33:01

Very good. Lymphoma

33:03

got the most votes.

33:05

Um, I was thinking of putting

33:07

metastasis as one of the, um—

33:11

choices.

33:12

But then again, um, kind of, you know,

33:15

then I'm sure the votes would be split.

33:17

Um, so metastasis can be FDG-avid with

33:21

PET too. Uh, in this case it was lymphoma.

33:24

Um, most of—majority of you are right.

33:26

And with lymphoma, um, there could be primary

33:30

involvement of the spleen or, uh, the primary—

33:34

um—

33:35

involvement, that there could

33:36

be primary splenic lymphoma.

33:37

Spleen could be involved secondarily

33:39

from, you know, diffuse lymphoma.

33:41

Lymphoma.

33:43

The splenic masses can do show, the

33:45

spleen can show diffuse enlargement.

33:48

Uh, there could be a dominant hypodense mass, or

33:51

there could be numerous, multiple small hypodense lesions.

33:54

Uh, they can take avid, uh, FDG uptake.

33:58

And, um, this is—

34:01

more commonly involved

34:03

secondarily. And, um, approximately 30%

34:07

of the Hodgkin lymphomas and 30% of

34:10

non-Hodgkin lymphomas can involve the spleen.

34:13

Primary splenic lymphoma is extremely

34:16

rare, and the incidence is less than 1%.

34:19

And when the primary lymphomas, it can

34:22

either be diffuse large B-cell or mantle

34:24

cell lymphomas. And, um, FDG PET can be

34:28

uh, helpful because they are, um, uh, really FDG-avid.

34:34

And, uh, this was another example in which the

34:37

spleen was—in that case, that was considered

34:40

to be a primary lymphoma of the spleen.

34:42

Uh, this is another companion case where.

34:45

The rim showed FDG avidity of this mass

34:48

in the spleen, which is also enlarged.

34:51

Uh, but there was central necrosis

34:52

which did not show much FDG avidity.

34:55

This was secondary involvement of the spleen.

34:57

And you see lots of FDG-avid lymph nodes

35:00

in this person, in the retroperitoneum,

35:02

mediastinum, and also in the neck.

35:06

Um, this is a third, uh, companion

35:09

case, or a second companion case.

35:12

Third case of lymphoma.

35:13

Uh, this was a primary diffuse large

35:16

B-cell lymphoma arising from the

35:19

splenic hilum, growing into the pancreas.

35:22

In fact, some of these, uh, lymphomas can

35:25

really have a large mass effect that they

35:28

can grow extensively, involve the surrounding

35:30

organs, and, uh, grow to involve the, um,

35:33

most of the pancreas.

35:39

Okay.

35:39

This is question number 10.

35:42

Um, this patient has, um, yeah, you could, um, look at

35:47

the imaging findings and, uh, uh, what is your answer?

35:51

Um, this is T2-weighted image.

35:55

And, uh, you have post-contrast

35:58

image and a non-contrast image in the

36:01

center and a diffusion-weighted image.

36:04

And this mass has been stable over two years.

36:12

You know, majority of the answers was sarcoidosis.

36:16

Uh, that is a good answer.

36:18

Um, so sarcoidosis, if it is

36:21

untreated, can be progressive.

36:23

Um, and, uh, also in this case,

36:26

just the spleen is involved.

36:28

There is no involvement of the liver.

36:31

So this was a case of hemangiomas, and, uh, it is.

36:36

Uh, some of these lesions are really T2-

36:39

hyperintense, but the lesions along the medial

36:42

aspect of the spleen do show some enhancement.

36:45

So this was multiple splenic hemangiomas and, uh,

36:49

the hint towards the diagnosis is the stability.

36:52

So this was the CT from two years ago, and

36:55

pretty much the picture looks identical.

36:57

And, uh, I showed this case as a segue to

37:00

this next case, which does not have a question

37:03

because if it did, I think everyone would.

37:05

Of you would have guessed right, there

37:07

are very few very aggressive tumors of

37:09

the spleen, and this is one of them.

37:12

Uh, this patient presented with eight months of

37:14

gradually worsening left upper quadrant pain,

37:17

15-pound weight loss, decreased appetite, you

37:20

know, all features suggestive of malignancy.

37:22

And there is this large splenic

37:24

mass with heterogeneous enhancement.

37:26

Uh, the spleen has still maintained its kind shape,

37:30

uh, but it has significantly increased in size.

37:33

This mass appears heterogeneous on, um,

37:36

ultrasound, and this was an angiosarcoma.

37:40

Sometimes when there is diffuse involvement of the

37:42

spleen, in the previous case, there is a, uh, like the

37:45

hemangioma case that we just discussed, there is a

37:48

concern for, uh, whether this could be angiosarcoma.

37:52

And, uh, but angiosarcomas kind of are not stable.

37:56

Uh, they're very aggressive.

37:57

They can grow rapidly.

37:59

And, uh, um, they are also

38:03

associated with splenomegaly.

38:05

Uh, these are rare neoplasms though.

38:08

Um, they're seen in older individuals.

38:10

Patients can present with a lot of symptoms, including

38:13

thrombocytopenia because of the splenic size.

38:16

And, um, um, this is treated with surgical resection.

38:23

On, uh, we just discussed ultrasound features. On CT,

38:27

it's a heterogeneous mass, poorly

38:29

marginated, and that's the reason why

38:31

the entire spleen should be removed.

38:33

They can bleed.

38:36

Next case.

38:38

Um, a lot of images, but I'll explain

38:40

this first before going to the question.

38:42

Uh, this is a patient, uh, these are the

38:45

images from most recent images on this patient.

38:49

There is a splenic lesion with these features.

38:52

And these are the images from, uh, three months

38:57

ago, where the lesion measured slightly smaller.

39:01

And these are the images from, um, so actually

39:04

these are the images from a year ago.

39:06

Uh, I, um, apologies for this typo.

39:11

Uh, these were not seen a year ago.

39:15

So what is the diagnosis based

39:17

on these imaging findings?

39:24

Is this a hemangioma, lymphoma,

39:26

angiosarcoma, or metastasis?

39:32

Great.

39:33

Overwhelmingly, um, most of you picked up, uh,

39:37

metastasis, uh, definitely a diagnosis of

39:42

exclusion, but also in this case, uh, you may have

39:45

noticed that the liver also has similar lesions.

39:48

Lots of these, in fact, including this large

39:51

mass, which almost looks like this lesion.

39:54

So this was indeed a metastasis from HCC.

39:58

Now, um, the patient did not undergo

40:02

diagnosis, uh, did not undergo biopsy.

40:05

The diagnosis was based on imaging

40:07

features alone, uh, the metastatic lesions.

40:10

In the spleen.

40:11

Some you do usually look like

40:12

they're primary malignancies.

40:14

And that helps in the, um, um, uh, in us

40:18

making the diagnosis based on imaging alone.

40:21

Now, metastasis to the spleen is rare,

40:23

especially isolated metastasis to the

40:25

spleen alone without metastasis to the rest

40:28

of the other organs is extremely rare.

40:31

Uh, usually you do see metastasis in other organs too.

40:35

Um, most common lesion, most common malignancy to

40:39

present with isolated splenic metastasis is melanoma.

40:43

You can see metastasis from breast, liver,

40:45

colorectal, renal, several other malignancies,

40:48

and as you saw on these images, MRI is

40:51

extraordinarily good in localizing these

40:54

lesions and characterizing these lesions.

40:56

In this case, it was too dark.

40:59

Um, it showed enhancement on arterial

41:02

phase and maybe washout on delayed phases.

41:04

It was barely seen on CT.

41:06

And also, with the patient's arm on

41:08

the side, there are some artifacts too.

41:10

So MRI is excellent for, uh,

41:12

evaluation of metastasis to the spleen.

41:18

So case 12, uh, this is a great case.

41:21

I will provide no history.

41:23

And could you make the diagnosis on imaging alone?

41:27

Um, you could put up the question.

41:29

Um, now, Ryan?

41:30

Yes.

41:32

So what is the diagnosis?

41:34

Is this sarcoidosis, lymphoma,

41:37

fungal abscesses, or metastasis?

41:41

The top row of images are the most recent

41:43

images, and you have images from the

41:47

uh, from about two years ago in the bottom row.

41:53

This is indeed sarcoidosis and, um, unlike

41:57

the previous case with multiple hemangiomas,

42:00

which only involve the spleen, these lesions have

42:03

involved both the liver and the spleen and the,

42:07

um, mediastinal lymph nodes, lymph nodes elsewhere.

42:11

And also they show this classic

42:12

perilymphatic distribution of the nodules.

42:15

This patient had.

42:16

Treatment with steroids and improved, and

42:19

these lesions subsequently disappeared and at

42:22

least they became very inconspicuous.

42:25

This is like the most dramatic

42:26

improvement of sarcoidosis I have seen.

42:29

So that you are all, uh, right, this is

42:32

indeed sarcoidosis and, um, uh, kind of,

42:37

it has these multiple nodules and, uh.

42:41

There is, if there is a chest CT, and

42:43

usually in most of these patients there

42:44

is already a diagnosis of sarcoidosis and

42:47

these are the abdominal manifestations.

42:49

Again, MRI is definitely better than CT.

42:52

In CT too, you will see this as hyperdense nodules.

42:57

Next question.

43:01

So what is the diagnosis in this case? I'm

43:05

not gonna tell you what sequences they are.

43:11

Perfect.

43:11

So this is indeed hemochromatosis.

43:15

Um, this is out-of-phase images because it has this

43:19

classic India ink lining of the organs, and this

43:24

is in-phase images and there is signal dropout.

43:28

Look at the average numbers.

43:30

It is 18 and.

43:32

The average number on out-of-phase images was

43:35

50, around 59, so it dropped from 59 to 18,

43:40

and so there is dropout on in-phase images.

43:44

With iron deposition.

43:46

Also there is dropout of signal within the liver.

43:49

So there is iron deposition

43:50

in both liver and the spleen.

43:53

T2 images are also helpful.

43:54

The T1 and T2 images, the liver and the spleen

43:57

are both dark on T2, which can be seen with, um,

44:02

uh, iron deposition in the liver and the spleen.

44:05

So this was a case of hemochromatosis and

44:08

hemochromatosis can be primary and secondary,

44:10

which is beyond the scope of this discussion.

44:13

But.

44:14

Just to differentiate, in secondary

44:16

hemochromatosis, spleen is mainly involved.

44:19

Uh, the bone marrow can be involved.

44:21

It spares the pancreas, while in

44:23

primary hemochromatosis, uh, like

44:26

in this case, liver is involved.

44:28

Patients can present with cirrhosis.

44:30

Uh, pancreas is involved, pituitary, and also majority

44:34

of these patients have poor liver function too.

44:38

We'll just do this question and then, uh,

44:40

we will, I'll just showcase cases, uh,

44:41

the last few slides and no more questions.

44:43

So let's do this one last polling question.

44:47

Uh, this is an 80-year-old woman.

44:49

Yes.

44:50

Uh, 80-year-old woman with altered mental status.

44:52

And, um, uh, these are the images of the spleen.

44:57

Based on these images, what is the diagnosis?

45:01

So I quickly changed the MR images of the brain.

45:04

I will go back to those.

45:06

These were considered an infarct,

45:08

secondary to septic, uh, emboli.

45:12

And these are the abdominal CT findings.

45:17

So is this, uh, is this lesion which

45:19

you see in the spleen, is this an

45:21

infarct, abscess, pseudocyst, or a hydatid cyst?

45:27

Perfect.

45:28

So this is indeed an abscess.

45:31

There are, uh, quite a few who also

45:34

thought this could be splenic infarct.

45:36

Now any hypodense lesion, you should, uh, consider

45:40

the etiologies of a hypodense splenic mass,

45:43

or an abscess, or a hematoma, or an infarct.

45:46

In this case, there is some

45:48

reactive fluid around this spleen.

45:50

Looks like there has been inflammation in this.

45:52

Explain to, uh, in this patient there

45:55

was elevated white count and there was

45:57

finding of septic emboli in the brain.

46:00

So this patient had sepsis and the splenic abscess,

46:04

uh, was the component of the sepsis in this patient.

46:07

Um, it was drained.

46:09

The patient has bacterial angio-sepsis.

46:12

Uh, it grew some polymicrobial.

46:16

Um, infarct is mainly wedge-shaped.

46:20

And, um, hematomas can sometimes look like

46:24

this, but they do have hyperdense contents,

46:26

which is the hemorrhagic components.

46:28

Uh, patient.

46:29

If this patient had pancreatitis, then

46:31

cyst should definitely be considered.

46:33

Uh, splenic hydatid cysts have more of a,

46:36

a multiseptated appearance, and, uh,

46:39

there would be more in the history.

46:41

Uh.

46:42

Like this patient would be, uh, would have

46:44

been from an area endemic to hydatid cyst.

46:47

Hydatid cyst.

46:49

Let's look at next few cases.

46:50

Uh, we will not be doing the polling.

46:52

Um, just in the interest of time, I will be showing

46:56

these cases to you and I will be telling the answers.

46:59

Uh, so this is a patient

47:01

post-trauma and we see this wedge.

47:04

Areas arising from the capsule.

47:07

Now this could be an infarct because infarcts

47:10

are wedge-shaped hypodensities too.

47:14

Uh, but also if you see closely, there are few

47:16

more and they're kind of more jagged and irregular.

47:19

So this was a case of splenic laceration.

47:23

And also usually splenic laceration

47:25

is also associated with trace amount

47:27

of perisplenic fluid in these cases.

47:30

In this, um, for splenic lacerations, we do

47:34

follow the AAST grading for splenic

47:37

injury, which is American Association

47:40

um,

47:41

for the Surgery of Trauma

47:43

Group, uh, grading suggestion.

47:45

This is open access.

47:46

This is a resource available for everyone to refer to.

47:50

Uh, kind of, um, it's good to mention

47:53

this in your report, uh, for the acute care

47:55

surgery to kind of have an, um, have an

47:58

assessment of the extent of injury to the spleen.

48:01

In this patient, uh, there was possible

48:04

capsular tear with possibly one to

48:07

three centimeter parenchymal depth invasion.

48:10

This was not an arterial phase image,

48:11

but, and we definitely didn't see any

48:13

involvement of the macular vessel.

48:15

So this was probably, uh, grade

48:18

two laceration of the spleen.

48:21

In this next companion case, this person had

48:24

a more, uh, kind of, uh, aggressive injury.

48:28

Uh, this is again, a young man with trauma.

48:31

You see there is no flow in

48:33

this portion of the spleen.

48:35

There is no vascularity.

48:36

You do see this hyperdense focus.

48:39

Um,

48:43

and there are like more areas of, uh, laceration too.

48:47

There is this hyperdense focus, which is

48:49

active extravasation, uh, with active bleed.

48:53

And if the patient is unstable, these patients

48:55

are taken to surgery and the spleen is removed.

48:57

Or if the patient is stable,

48:59

splenic artery embolization can be done.

49:02

This was another case in which the,

49:05

there was not much splenic fluid.

49:08

There was this wisp of contrast as we describe

49:11

on CT, which was suggestive of extravasation.

49:14

So patient, uh, was not extremely unstable,

49:18

but the, uh, team was worried about the patient

49:21

potentially becoming, uh, hemodynamically unstable.

49:25

So they requested an, um, angiogram

49:28

and with potential embolization.

49:30

So on the angiogram, you see a lot of these areas.

49:35

Of, um, enhancement.

49:38

There was no contrast extravasation, there

49:41

was no wisp of contrast you would see with

49:43

active bleeding, but you saw these multiple,

49:46

like nodular small areas in the spleen.

49:49

Um, they did.

49:51

Embolize a portion, gelfoam embolize a portion

49:55

of, um, a segment of spleen, which they thought

49:58

could be the one which was involved with this.

50:01

Uh, um, this area of extravasation,

50:04

although they did not see any active bleed.

50:07

And, um, patient underwent, uh, CT post.

50:12

Um.

50:13

Embolization, and you'll see these

50:15

multiple small areas of enhancement.

50:18

Again, it doesn't look like extravasated

50:21

contrast, but it looks like multiple

50:23

small areas of contrast, um, enhancement.

50:28

So, um, the reason I showed you this case was

50:32

I wanted to introduce you to a new terminology,

50:35

which I learned while interpreting this case.

50:38

Um, this is called Surat spleen, based

50:44

on the painter who kind of painted, uh, used

50:48

multiple dots to create these beautiful paintings.

50:51

Uh, so these are actually, can be seen with

50:54

blunt trauma, which was, uh, in our case.

50:57

And the reason for these areas of enhancement

51:00

is because of sinusoidal stasis of contrast.

51:04

It could be because of arteriovenous

51:06

tiny aneurysms or pseudoaneurysms that can develop from

51:09

blunt trauma, or also it could be contrast leakage from

51:12

fragmented sinusoids, and these are self-resolving.

51:16

So it's kind of nice to know this phenomenon that

51:19

if the patient's hemodynamically stable and all you

51:22

see is these tiny areas of enhancement, then this may

51:24

be Surat spleen and you could observe this patient.

51:30

Just a last couple of cases

51:32

before we look at the questions.

51:33

Um, this is to show the, um, this is

51:37

a SPECT image, uh, few SPECT images.

51:40

This is a SPECT image to show this,

51:42

uh, sulfur colloid study, uh, importance

51:44

in this enhancing focus in the spleen.

51:47

This was a case of, uh, um,

51:51

this was a case of splenic, uh.

51:54

Um, intrapancreatic spleen, uh,

51:57

which showed enhancement and also,

52:01

um, it did uptake the sulfur colloid.

52:04

And, uh, another few SPECT images to show splenosis.

52:08

Remember, splenosis is acquired.

52:11

Polysplenia, splenunculi, accessory spleen.

52:13

They're all congenital.

52:15

And, uh, this patient had a splenic injury as a child

52:18

with multiple splenic rests throughout the body in the

52:22

left lower quadrant, which all took up sulfur colloid.

52:25

Um.

52:28

On the sulfur colloid studies,

52:29

you'll see all those areas of splenosis.

52:32

So in summary, imaging plays a major role

52:34

in the diagnosis of splenic abnormalities.

52:37

Some of the splenic masses will have

52:40

non-specific features, but it's important

52:42

to recognize the more aggressive features.

52:45

Um, also correlate with the symptoms of the patients.

52:48

If the mass is symptomatic, it may,

52:51

the spleen may have to be removed.

52:53

And also, um, just familiarity with these imaging

52:56

features prevents unnecessary interventions.

52:59

These are my references.

53:00

Thank you so much for your attention.

53:02

Um, I could answer a couple of, uh, questions.

53:07

Um, so this is, uh, how do you

53:11

discriminate between splenic cyst and

53:13

lymphangioma, um, in the, in the case?

53:17

Um, that, this is a good question.

53:19

So it is.

53:21

Not hard to, it is some, it can be sometimes

53:24

hard to differentiate, but lymphangiomas usually

53:27

have septations, which may enhance. Either way,

53:30

they're both considered benign.

53:32

If you cannot differentiate, uh, you can call them.

53:36

Um, you could just give both in your differential.

53:39

You're absolutely right.

53:40

Sometimes we do see fluid-fluid level, um, in

53:44

cases of hemorrhage or if there are proteinaceous

53:46

debris, but splenic cysts are usually.

53:49

Unilocular and lymphangioma can have

53:53

multiple septations, can be multilocular.

53:56

Giving both in the differential is fine.

53:58

They're both benign and no need for follow-up.

54:01

Uh, next question is what are the

54:03

MRI features expected in lymphoma?

54:05

This is a great question, actually.

54:07

There are some nice articles.

54:09

Um.

54:10

Of just, uh, description of, um, they describe

54:15

various patterns of enhancement, uh, of lymphoma.

54:19

Most common one is an avidly FDG-avid mass,

54:24

and you'll also see multiple FDG-avid foci

54:27

everywhere in the body, on MRIs specifically.

54:32

Um, it doesn't, it has really non-specific features.

54:35

It can hypoenhance, it can, depending on,

54:39

um, whether there is central necrosis or not.

54:42

Um, it doesn't really have any.

54:44

Specific features on MRI.

54:47

Uh, if there are no other systemic

54:49

features, I would get, um, a PET-CT done.

54:53

Also, sometimes if there is no lymphadenopathy

54:56

elsewhere in the body, uh, you

54:59

should, uh, sometimes tissue biopsies should be done.

55:04

We expect to have, uh, in the case of hemangioma,

55:07

we expect to have classic enhancement pattern.

55:10

You're right.

55:11

Um, there are articles which describe, um.

55:15

The classic discontinuous nodular enhancement

55:18

seen in the spleen with the hemangiomas, but in

55:22

my experience, majority of the hemangiomas I have

55:26

seen, they do not show this classic discontinuous

55:29

enhancement, which you see because in the liver,

55:33

there is a large central hypodense area, and

55:36

then you see this peripheral nodular enhancement,

55:38

so you can appreciate it better. In the spleen,

55:40

it kind of has more of a solid appearance.

55:44

It can also have cystic appearance, as we see.

55:47

Uh, so, um, in hemangiomas, that's the

55:51

thing with splenic masses, you could see

55:54

a nodular enhancement, but if you don't

55:56

see it, it could still be a hemangioma.

56:00

And, uh, pancreatic splenule simulates an insulinoma.

56:03

Lymphomas, you're absolutely right.

56:05

It can look like neuroendocrine tumor.

56:07

And that was the purpose of my previous case.

56:10

Um, so.

56:12

On the MRI, we cannot differentiate

56:14

these two entities, and that's why

56:16

we do the sulfur colloid study.

56:18

Uh, so, uh, the nuclear medicine

56:20

studies to show that the splenic tissue

56:23

takes up the, um, the tracer.

56:27

And the neuroendocrine tumor does

56:29

not, if it is still in doubt.

56:32

Uh, they do endoscopic ultrasound with

56:34

biopsy, and also the intrapancreatic spleen

56:38

can, sometimes you can see a little bit of

56:40

capsule with it, if it is large enough.

56:43

It has enhancement patterns, especially in

56:45

arterial phase, identical to that of, uh,

56:48

spleen, and you're able to differentiate it.

56:52

Um, sorry.

56:53

The vaccine-related findings in spleen is a long topic.

56:57

I won't be able to cover that today.

57:00

Um, yes, we do.

57:02

We don't see a lot of.

57:03

Next question is, um, uh, did you

57:07

see many SANT, uh, in your practice?

57:10

We do see.

57:11

Um, we have, from my experience, I've been working

57:14

in this institution for three and a half years.

57:16

I have seen two cases of SANT, so not

57:19

a lot of cases, but again, our

57:21

center is a tertiary referral center.

57:23

So we do get referred here, um, with cases,

57:27

and a few of my colleagues have seen this.

57:29

So it depends on where you practice.

57:31

So we.

57:32

Not a lot, but we have seen a few cases. Uh, role

57:35

of diffusion-weighted imaging and ADC in lymphoma.

57:38

This is a very good question.

57:39

So I actually looked this up before this

57:41

talk because the spleen is so bright.

57:46

It is just.

57:48

Usually, and it is only mainly useful

57:51

for localizing the lesions, if at all.

57:54

So I don't know, there's not a lot of literature

57:56

out there about, uh, diffusion-weighted

57:59

and ADC in lymphoma.

58:02

I don't have much experience with this.

58:04

We kind of have not diagnosed this just based on

58:07

diffusion-weighted imaging findings, but rather

58:09

by the rest of the findings, you know, post-contrast

58:11

enhancement, T2-weighted appearance and also

58:14

and a PET if it has been done with this study.

58:18

Alright.

58:18

I think I answered most of them.

58:19

Um,

58:20

No, that looks like all the questions.

58:22

Uh, awesome.

58:23

Yeah.

58:24

Thank you so much, guys.

58:25

Yeah.

58:25

And just as we bring this to a close,

58:27

I wanna thank Dr. Thimmappa for this lecture.

58:29

And thanks to all of you for

58:30

participating in our Noon Conference.

58:32

I'll remind you that this conference will

58:34

be available on demand on mri-online.com,

58:38

in addition to all previous Noon Conferences.

58:40

Be sure to join us again on Wednesday

58:42

for a lecture from Dr. Ibrahim on

58:45

imaging of head and neck infections.

58:47

You can register for that at mri-online.com and follow

58:51

us on social media at MRI Online for updates

58:55

and reminders on upcoming Noon Conferences.

58:58

Thanks again and have a great day.