Benign Focal Liver Lesions - HD

Benign Focal Liver Lesions

Thank you very much.

My talk next will cover Benign Focal Liver Lesions.

That is a huge challenge because there are so many and it is partly a little bit difficult.

Let me start.

First of all, we are very happy that the Americans are joining now, the contrast family.

I think it's now four or five years weeks ago that LumaSon, that is the name for SonoVue in the US, has now been approved by the FDA in the US.

That is of course a huge step forward.

As Barry Goldberg said once, the US is the third world country in regards of the contrast agents.

That is no longer true because they are joining us.

Most Common Benign Hepatic Tumors

Most common benign hepatic tumors, benign tumors, number one is of course focal fatty changes.

This is very often finding cysts, hemangiomas, and I will cover in my talk most the most common benign lesions.

I will cover the hemangiomas, typical and atypical ones, the FNH, typical atypical infectious disease, very small one.

Just have only one example for that adenoma and the classification of adenomas.

That is a huge discussion point among not only the ultrasound specialists, lipoma, AML granulomas, biliary hamartomas, mucinous cystadenomas inflammatory pseudotumor and focal nodular hyperplasia.

They may have these echogenic lesion in the liver that enhance just like the liver.

You don't see any difference or you cannot really characterize by contrast.

I will not cover these ones, but let me start with a typical hemangioma.

You already heard that you have a peripheral nodular enhancement during the arterial phase, a progressive central filling, starting in these peripheral nodules to a partial complete filling.

You have an enhancement that is sustained through the late and the post vascular phase.

CEUS makes an accurate diagnosis in 95% of the cases and specifically of close to a hundred percent.

Why is it only 95%?

Because some of the hemangiomas, mostly those that are have a medium size or very small, they are completely thrombosed.

This is the challenge for I think all imaging modalities.

Let me start with this case.

You see two typical hemangiomas in gray scale.

What is typical, typical is these echogenic rim around it.

You do not see it all the time, but if you see that it's highly suggestive of a hemangioma.

You also see a posterior enhancement.

When you give contrast, have in mind please that all hemangiomas are supplied by arteries.

The arteries, they push the blood into the small lacunae of a hemangioma.

What you can see here is when the loop is running, again, I can show you here are these small nodules here that are filled with blood and contrast.

But if the loop is running, again, you can see this is the artery.

You see the enhancement only in the artery.

There's no portal vein.

Now the portal vein is coming.

Hemangiomas are supplied by arteries, and you can see that the best modality to see and demonstrate that is contrast enhanced ultrasound.

Of course, if you wait a little bit longer, then you can see the hemangiomas are nearly completely filled.

This is after one minute.

This is not the challenge, okay?

Of course, hemangiomas might grow.

Very often we get patients who have a hemangioma that was diagnosed previously, and then they are referred again because the hemangioma has grown, of course, hemangiomas might grow.

There is a nice study by Yi published in 2007, and they found out that around about 78% of hemangiomas grow in size.

What is the diagnostic confidence of B mode imaging of liver hemangiomas?

Because when I started to do contrast on hemangiomas, very well known colleagues in ultrasound came to me and said, come on, you are joking.

You do not read contrasts for hemangiomas.

This is such an easy diagnosis.

They are correct, but only if you look at patients who have a very low risk for a malignant disease.

Healthy patients incidentally finding of a hemangioma, and it looks typical like a hemangioma, they have no laboratory findings that point to a another disease.

They are healthy subjects.

If you find in a healthy subject, a lesion that looks like a hemangioma, it is a hemangioma, but if you have a hemangioma in a population at risk, then the number drops down to 50%.

Only 50% of those who look like hemangiomas are hemangiomas in patients who have chronic hepatitis B, C or who have a history of malignancy.

That is important to have in mind.

Atypical Hemangiomas

Atypical hemangiomas, and I concentrate more on the atypical ones because the typical ones are so typical that I will not cover more cases of that.

Mostly they are hypo echoic.

The question behind it is, do we have a fatty liver disease?

Because in fatty liver diseases, mostly all or nearly all liver lesions look hypo echoic, we have sclerosing tissue, calcification hemorrhage in atypical hemangiomas.

They might be completely thrombosed.

They are hard on elastography.

They have a centrifugal filling of contrast that is very rare, but you can see that you have shunting and you have wash out.

Okay?

This is another case of a 23-year-old male who came with a tumor of the testicular tumor, highly malignant, and he came with this lesion in the liver, and that was of course a hemangioma, but then he received chemotherapy.

Under chemotherapy, the liver experienced fatty changes.

Due to the fatty liver disease that he now has under three courses of chemotherapy, the hemangioma looks like a something else, but it doesn't look any typical more for a hemangioma.

But of course, it is still the same.

Let me show you this case here.

This is a Turkish lady, 52 years old, and she has three hypo echoic lesions in a slightly fatty liver disease.

The first idea of course was where is the biopsy needle?

But first of all, we do contrast.

Of course, in contrast, surprise, this is a typical hemangioma with a peripheral nodular enhancement.

When we look later, nearly completely filled.

There is no discussion about that.

You don't need any other imaging modality.

You don't need biopsy, nothing.

Diagnosis confirmed.

What about this case?

This is a patient with a colon cancer, and he had a lesion in segment seven with a central calcification.

Again, we were looking now for elastography, and it looks like a hard tumor.

Then we look for contrast.

In contrast, again, you can see typical hemangioma, no question about that.

Here is the late phase where you see it is a progressive central fetal filling.

This is another case.

This looks like a typical hemangioma.

When you look at the early arterial phase, then you can see that the enhancement starts in the center of the tumor.

We have a centrifugal filling of this hemangioma, and here is an FNH.

We have an FNH plus a hemangioma.

We wait a little bit, this is after one minute, and then you can see a progressive filling.

We again wait a little bit and it proceeds to the periphery.

After two minutes completely filled and it is hyper vascularized.

Okay?

This is a patient who was in another hospital and it was suspicious this lesion.

They said we biopsied, they did three fine needle biopsy, and all the biopsies showed no pathology.

The patient was really upset about that, and he left the hospital, came to our place, and we were looking at this lesion and found out it is really not typical.

This is the arterial phase.

You can see that the contrast is arriving.

Here is the enhancement, and it is dominantly in the periphery, it is enhancing, but also in the center you can see some enhancement.

We wait, and this is after one minute, and then you can see the periphery is looks like it is washing out and the center is taking up contrast.

Now we are at two minutes.

It is washed out.

We biopsied that with the core biopsy and the core biopsy said, this is a sclerosing hemangioma.

This is not easy to make this diagnosis.

I must say from today, and when I review this case, I would say I would do it again to biopsy this lesion.

It was not easy.

This is another typical hemangioma and it is filling very, very quickly within seconds, a few seconds.

This is a high flow hemangioma or a very quick filling hemangioma.

What you can also see is some shunting.

You can see the shunting, you can see a wedge shaped shunting, just like I showed you before in these malignant tumor of the liver, there was also some shunting, but here also shunting of these hemangiomas.

That is not a rare finding.

You can see that quite often in hemangiomas, if you look very carefully during the arterial phase, and this is later of course, during the late phase or this is the late portal venous phase, you don't see any enhancement.

Okay, this is again the still frame from these arterial phase after 22 seconds.

Okay, this is another lesion in the segment five.

What is special about it is here is a lesion and then you can see a wedge shaped hypoechoic area developing here along the portal vein tract.

What is that?

We did color doppler.

Color doppler is sometimes very helpful, so we do that all the time.

But in this case, what you can see immediately is that there is a reverse flow in the portal vein.

We have the artery with the correct flow direction and the portal vein flowing backwards.

There must be a lesion with shunts.

The question is, what kind of lesion is that?

We give contrast.

We give contrast, and you can see two hemangiomas, two classical hemangiomas peripheral enhancement.

We followed this lesion until the late phase and it was completely filled.

This is again a accumulation mode.

You can see quite nicely here, the supplying artery.

I show you this is the supplying artery of the hemangioma.

WFUMB Guidelines for Hemangiomas

This is what the WFUMB guidelines said.

We already heard from David about the criteria that have been written down in the WFUMB and EFSUMB guidelines.

Tips and Tricks for Hemangiomas

Some tips and tricks.

Number one, consider that an echogenic lesion in B mode may not be canceled out completely.

When you have a really very outstanding hypoechoic lesion and then you switch to contrast mode.

Maybe the lesion is not canceled out, so it stays there.

When you give contrast and you see that the contrast is being washed out over time, then of course the hypoechoic lesion stays in the image.

That is something that you have to have in mind.

TI see technique may help to see if it is really washing out to the level before contrast injection.

Do not scan continuously in one scan plane.

I think this is one of the most important points because then you destroy bubbles and the longer you scan, the more bubbles you destroy.

Then it looks like that the lesion has been washed out.

But that is artificial, that is due to your scanning technique.

Don't do that.

As soon as you have realized, yes, we have a peripheral nodular enhancement, stop scanning, wait a bit and then scan again.

Then you can see a progressive.

Do not scan and say, oh, I need to record it over five minutes.

Don't do that.

Then you have hemangiomas that look different and not like hemangiomas.

Carefully watch the filling of small peripheral nodules even when they are very small because some hemangiomas are thrombosed, partly thrombosed.

Maybe you only see these peripheral nodules being early enhanced.

This is sufficient to make the diagnosis of a hemangioma.

Be very careful in looking for these peripheral nodules.

No contrast uptake at any time.

Completely from both hemangiomas are re-challenged.

The ones that we have seen, they all went to CT on the CT or MRI, they said highly suspicious for metastasis because they never take up contrast.

When we look at these lesions and we saw no contrast uptake, the histology proved that it was a complete thrombosing hemangioma.

I am not saying that this is really a proof, but it is highly suggestive of benign lesion.

Liver Abscess

Okay, liver abscess, of course, it is an easy diagnosis.

This is a patient who had a liver abscess.

He had received drainage, and after that, again, he developed fever and pain in his epigastrium.

Here you can see it is again a recurrence of these abscess, and you can see the peripheral hyper enhancement around these abscess.

This is typical like in any other imaging modality.

That is not a challenge.

I think for any modality that you use.

Focal Nodular Hyperplasia (FNH)

FNH, this is the second most common benign solid tumor.

It is a result of a hyperplastic response of hepatocytes to the presence of a preexisting vascular malformation.

There is an old story that says, okay, if you take any hormones or yeah, then young women should not use oral contraceptives anymore.

If the FNH has been diagnosed, that is not true.

It is only true for adenoma, but not for FNHs.

An ultrasound shows in two thirds of the cases, mostly round shaped echogenic to isoechoic.

They have central scars.

This is of the central scars being missed in 30% of the cases.

The ratio between male and female or female to male is five to one, to nine to one hard on elastography.

This is an important feature to differentiate from other tumors.

Color doppler, we see the spoke wheel sign, and in CEUS we see a tumor supplied by a central or peripheral artery or arteries, more than one, corkscrew like tumor supplying artery.

But this is of course not specific.

You can see that also in other tumors that are hyper vascularized spoke wheel sign arteries not accompanied by portal veins, a centrifugal enhancement causing a quick growth of the lesion.

If you give the contrast and you have a high temporal resolution, then you can see the tumor starts in the center and then it is growing within seconds.

That is typical for FNH iso or hyper enhancement until the late phase and the central scar and arterial portal shunting may occur.

This is an example of an FNH of eight centimeters.

You can see during the arterial phase, the wash in this is again a accumulation image.

You can see quite nicely.

This is your supplying artery, the vasculature, but you can see the vasculature better if you not using this technique.

But if we switch to B flow with contrast, B flow with contrast means we have a subtraction technique and due to subtraction technique, you will not see the stationary echoes.

You only see bubbles that are moving.

I show you how that looks like.

It looks like that you only see the vessels.

What you can see is a, not only one, but you can see multiple spoke wheel pattern of arteries.

At least you can see three, I have no pointer here.

It is not working.

But I think you can see it quite nicely in the center, left to the center and above another case.

Again, contrast is coming and the quality of a contrast setting can be seen in a FNH because the central scar is always there.

Most images that you can see, you can see the central scar only in the portal venous phase or the late phase, but it should be there, of course, also in the arterial phase.

That is something that demonstrates that the spatial resolution and the contrast resolution is so good here.

This is the central scar and it is also being seen during the arterial phase.

Contrast is coming, and yeah, here is the central scar.

Very nice to see during the arterial phase.

We have 19, 18 seconds now, and we can see it already.

This is a male, also.

Male patients have FNHs, and this is the within nine megahertz linear probe.

You can see the arteries.

They have a higher concentration of bubbles in the beginning, and you can see the spoke wheel pattern of the vasculature in the or the vessel morphology in the FNH.

Very nice to see, I think.

It is growing over time.

Okay, this is another patient also with two FNHs.

We are looking for the one that is not easy to see.

It is located in segment seven.

It is here.

When we give contrast and we do a sweep over these lesion, and you can see the supplying artery, tortuous artery, you can see the internal vasculature of the tumor.

Then we can have also an endless loop running like here.

Typical FNH, and we know this FNH now since a couple of years, it is not growing and it stays the same.

EFSUMB Guidelines for FNH

These are the EFSUMB guidelines.

David again already mentioned the typical features of a typical FNH in his talk.

Hepatocellular Adenoma (HCA)

Now we come to a most challenging part of the talk.

These are the hepatocellular adenomas.

There is a low incidence, three to four in a hundred thousand people in Europe, in America, it is lower in Asia, and 85% young women are affected, HCA rare in children, male and in the elderly.

The risk factors are in female, estrogen, steroids and androgenic.

These are the males who go for workouts.

They try to get more muscles.

They have androgens, and if they have these drugs, if they take these drugs, the risk of developing adenomas is higher.

80% we see patients with contraceptives.

The incidence is increasing in patients with type one glycogen storage disease and hemochromatosis solitary in 70 to 80% multiple in 20 to 30% hemorrhage may occur, and that may be life-threatening even.

It is especially can be expected in adenoma exceeding five centimeters.

Malignant transformation.

That is always a discussion through HCC in four to 7% only.

But the risk depends on the genetic type.

This is where the story starts.

We have four different types of adenomas.

We have the inflammatory HCA, 30 to 50% mutations.

Some mutations.

It is a genetic discussion how these subtypes look like.

Then we have the HNF1 alpha inactivated HCA, the 30 to 35%.

Then we have the beta catenin mutated HCA 10 to 15%, and we have the unclassified ones.

Is that important?

Well, it is important in that term that only the or the beta catenin mutated HCA, they have the highest level of transformation into malignant tumors.

This is why we should try to classify these.

The HNF1 alpha, they have very good prognosis, and the inflammatory HCA have 10% risk of malignant transformation.

We start with the inflammatory HCA.

This is the biggest group.

It is the most common subtype most in young women with oral contraceptives.

It is more often seen in fatty livers and the inflammatory infiltrates and hemorrhage can be found in 30%, and 10% malignant transformation, formerly known as telangiectatic FNHs.

This term should no longer be used as most of the authors state inflammatory HCA can mimic FNH on MRI.

Conventional pathology, using histopathology alone may lead to misclassification.

This again is an important point because it very much depends on who is looking at the histology.

I also have to say that not every pathologist believes in this new classification coming from Bordeaux.

Some of the pathologists still think the old way how to classify an adenoma is still working and it is sufficient.

But now when you look into literature, I think nearly all the papers been published in the recent years, they all refer to this new classification from Bordeaux.

Then we have these HNF1 alpha inactivated HCA most second most common one and least aggressive subtype only in women with oral contraceptives multiple in about 50% of cases prominent tumor steatosis.

This is important.

The tumor steatosis, you can see because on gray scale, they are hyperechoic lesions and the beta catenin mutated HCA, they have the highest risk of malignant transformation and more frequent in men contrast features from hyper to from hypo to hypoechoic, mostly sharp margins.

In most cases, they are soft on elastography.

Of course, if it starts bleeding, they are no longer soft.

They may become hard on elastography, but in the far most cases it is soft.

Therefore, elastography may play a role in distinguishing adenomas from FNHs early, but less enhancement in the arterial phase when compared to the FNH, no portal venous supply.

That may be one of the reasons for a washout centrifugal filling.

There is an important, maybe a different important difference to the FNH.

Although FNHs that are supplied by arteries that arise from the periphery may mimic also a centrifugal filling in up to 30%.

They are encapsulated.

That is what the pathologists are telling us.

With a non enhancing rim in the arterial phase later, they are isoenhanced.

That is important.

I will show you later.

This is a patient histology proven inflammatory HCA, you have two encapsulated adenomas.

This is color doppler.

You can see here quite nicely.

This is the adenoma.

This is one, and I have to admit, I did not see that before, but you will see that later on contrast, the second one.

Okay, now the contrast is coming and when you look at the filling type, it comes from more from the periphery and is filling the center.

Here.

You can see the capsule.

Here is the second one also with the capsule.

This is of course again a finding that you can only see when you have a very high spatial resolution contrast setting.

Otherwise, you will miss this capsule.

Again, here is the second one, and this is later, of course, after one minute, it is gone.

There is no capsule anymore because the capsule is not a non-viable tissue.

It is also viable tissue.

It is taken up contrast over time, but not in the arterial phase.

This is a hepatocellular adenoma.

This is the HNF1 alpha inactivated HCA.

Okay?

It is fatty liver, fatty tissue.

When you look at the contrast, it is taken up contrast, but over time starts to wash out.

This is another one.

Also, you can see on gray scale already that there is a encapsulated lesion and you can see it much better in contrast.

There is another hepatocellular adenoma.

Guidelines for Adenomas

These are the guidelines that are not very specific because as I just explained, there are multiple criteria that you have to look for in adenoma.

This is why it is always a challenge to make the diagnosis of an adenoma.

That is what I wanted to tell you about benign lesions.

I know there are many more benign lesions, and I did not have enough time to cover others, but hopefully these are the most important ones, I think.

Thank you very much.