0:00

This next case is a, uh, 30-year-old female

0:03

who presents with right upper quadrant pain.

0:05

An ultrasound was performed showing, uh, an

0:08

indeterminate liver mass for which an MRI was ordered.

0:11

So here we have the axial, uh, T2-weighted

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image, and we can see immediately a lesion

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bordering the right and left hepatic lobes.

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This can also be seen on the coronal image over here.

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And so we look at our, uh, T2-weighted image, we see the

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lesion here bordering the, uh, right and left hepatic lobes.

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Looks, uh, pretty well-defined, round and oval in shape.

0:31

And the content of it is certainly T2 hyperintense

0:34

for the most part, certainly the cephalad aspect of it.

0:38

But there is a discrete layer over here, and internally

0:42

below it, it is hypo to intermediate in signal.

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So it looks a little bit darker than CSF over there.

0:50

And we notice that its location is out at the

0:53

periphery. And is almost subcapsular in this location.

0:59

That becomes a very important descriptor of this lesion.

1:01

We can see it again here on the coronal images.

1:04

As we scroll through the remainder of the case, we can see

1:06

that there's not a whole lot of other cysts in this patient.

1:10

Only that one sort of isolated cyst, bordering the

1:14

right and left hepatic lobe, subcapsular in location.

1:17

There is another mass over here, which turns

1:19

out to be a different entity, and not a cyst,

1:21

which we're not going to talk about now.

1:23

But this is the only finding that we see.

1:25

that looks, uh, cystic in its appearance.

1:28

So we'll look at this systematically.

1:31

Moving on with our T1 in and out of phase images.

1:35

So here we have the T1 in and out of

1:37

phase images to evaluate this lesion.

1:39

On the out of phase image over here, we can

1:41

see that the mass, uh, is T1 hypointense.

1:44

On the in-phase image over here, we

1:46

can see it's also T1 hypointense.

1:48

There's no areas of signal loss on

1:51

the out of phase image to suggest fat.

1:53

And there's no areas of signal loss in the in-phase

1:55

images to suggest areas of increased susceptibility.

1:59

Move on to our T1 pre-contrast fat-saturated images.

2:03

And over here, we can again see that the

2:05

mass is pretty well-defined, relatively

2:09

hypointense on these T1-weighted images.

2:12

Um, and looks pretty otherwise simple, but we're

2:14

going to have to give intravenous contrast to

2:15

make sure that there's no internal enhancements.

2:18

So here we have the T1 dynamic post-

2:20

contrast imaging sequences and let's have

2:22

a look and see what this lesion does.

2:24

And the arterial phase images remains avascular,

2:28

pretty well-defined, similarly on the portal venous

2:31

phase images and the equilibrium phase images.

2:34

Looks, uh, pretty much like a simple cyst.

2:38

Going back to our T2-weighted images, again,

2:41

um, in all the imaging phases, this pretty much

2:44

looks like a simple cyst, but there is probably

2:46

a little bit of debris layering within it.

2:47

So, why am I discussing this particular case?

2:50

And the reason is because there is a very uncommon

2:54

entity called ciliated hepatic foregut cyst.

2:59

So, a ciliated hepatic foregut cyst

3:07

that, as mentioned, is very uncommon.

3:10

It's usually unilocular, about three centimeters in size.

3:14

On imaging it can have a little

3:15

bit of a debris level like this.

3:17

And it has a very characteristic location

3:20

that is often subcapsular and in segment four.

3:26

This happens to be probably bordering four

3:28

and eight, but close enough to segment four.

3:31

It tends to happen more commonly in

3:34

male patients who are middle-aged.

3:38

And it can present with right upper quadrant

3:42

pain because of that subcapsular location.

3:45

It can stretch the liver capsule over

3:47

here if it gets a little bit larger.

3:49

And it You know, I sort of suggest this entity in

3:53

instances when a patient comes in with pain, right

3:56

upper quadrant pain, no other findings, demographics

3:59

are pretty reasonable, and it's an isolated cyst.

4:02

Often with these lesions, the lesion

4:04

is isolated, as seen in this case.

4:07

If you look at patients who have liver cysts,

4:09

often they'll have more than one cyst in the liver.

4:12

They won't have 10 or 20.

4:13

As seen with polycystic liver disease, but they'll

4:16

have a scattering of, say, two or three cysts.

4:18

With this entity, it's often isolated,

4:20

subcapsular, segment four it can cause pain.

4:23

So why is it a big deal?

4:25

The reason is, is that there's about a

4:27

3% risk of malignant transformation.

4:32

And when that happens, it goes to squamous cell cancer.

4:36

And so if we're gonna think about this entity,

4:38

uh, we have to let the surgeons know about it.

4:40

They can go ahead and potentially resect it, uh, in time.