0:01

So during the embryonic age,

0:03

the spleen and the pancreas both develop

0:05

from the dorsal mesogastrium.

0:07

It is a kind of primitive mesentery,

0:09

which starts from gastrohepatic ligament,

0:12

encases the stomach, and then contains the bud

0:15

of the spleen as well as the pancreas.

0:18

So both of the organs actually move from the

0:19

dorsal mesogastrium to the retroperitoneum.

0:23

And it's possible during this, this

0:25

migration, some of the tissue of the spleen

0:28

can be retained during the, this passage

0:31

or the pathway in the retroperitoneum,

0:33

and can be anywhere in between the cords.

0:36

But most of the time,

0:38

the abnormal location of the spleen

0:40

tissue is in the pancreatic tail.

0:42

And that is seen as intrasplenic,

0:45

intrapancreatic spleenules on imaging.

0:48

And they can mimic some of the masses, and they

0:51

can be misinterpreted as the cancer sometimes.

0:54

So this is a case here, where we are trying to

0:58

characterize a lesion in the pancreatic tail.

1:01

And as we come here, we see a well-

1:04

defined lesion in the pancreatic tail.

1:07

Which is very well circumscribed,

1:09

well-defined, and looking almost like

1:12

a spleen on T2-weighted sequences.

1:16

And if we compare this intensity with the

1:17

pancreas, see this is the intensity of the

1:20

pancreas with lobulation and the fat inside,

1:23

see the intensity here versus the intensity of this

1:26

lesion, which just mimics the spleen altogether.

1:31

And otherwise, we do not see any

1:32

other lesion in the pancreas.

1:36

The pancreatic duct is not dilated.

1:38

And CVD is slightly prominent, but that can be

1:40

physiological because the gallbladder is missing.

1:45

And if we compare this lesion on other

1:47

intensities, other sequences, for example,

1:50

out of phase image here, we see the spleen tissue

1:56

and the tissue in the pancreatic tail,

1:59

which we have seen on the previous images in this

2:03

region, difficult to perceive on these images.

2:06

If we go to T1-weighted

2:09

fat-suppressed images,

2:11

we see this lesion here in the pancreatic

2:13

tail looking different than the rest of

2:16

the parenchyma on pre-contrast images.

2:19

See, the rest of the parenchyma is T1 slightly

2:21

hyperintense, but that looks slightly

2:23

different than the rest of the parenchyma.

2:27

And if we look for fat-suppressed T2-weighted

2:30

images here, the same kind of appearance is here.

2:34

The lesion is well-circumscribed and

2:36

mimics the spleen but looks slightly

2:39

different than the rest of the parenchyma.

2:42

And if we go to the post-contrast images

2:45

and see the enhancement pattern of this lesion,

2:49

so this is more enhancing than the rest of

2:50

the parenchyma, enhancing slightly more

2:51

than the parenchyma of the

2:54

pancreas, almost mimicking the spleen.

3:00

And the same thing happening here,

3:01

following the spleen.

3:04

So while a circumscribed lesion mostly in

3:06

the distal pancreas or the tail,

3:09

which follows the splenic parenchyma in all of the

3:11

sequences, whether it is pre-contrast or post-

3:14

contrast, is diagnostic of intraparenchymal

3:20

pancreatic splenules which can mimic a mass, as in this case.

3:26

You can confidently call it splenules if that

3:28

follows splenule in all those sequences.