0:00

So, we're just going to get right to it.

0:03

Um, so a little bit about the format, we're going

0:05

to show you an indicative image, then we're

0:09

going to preview the audience question, show you

0:13

the case, go through a little bit of didactics.

0:16

And then go to an audience poll for the question.

0:19

So, the first case we're going to review is

0:21

retropharyngeal lymph node of Rubier.

0:24

Um, so this is the indicative lesion, um, and, um,

0:30

think about it and we'll discuss it here shortly.

0:32

And this is the audience question that I want you

0:35

all to think about, um, as we do the presentation.

0:38

So, nodes of Rubier displace

0:40

the longest colic muscle how?

0:42

A, there's no displacement, B, anteriorly,

0:44

C, posteriorly, or D, I don't know.

0:49

So, um, let me show you the image.

0:52

So this is a patient that came to us, um,

0:55

with, uh, difficulty swallowing and some, um,

0:58

dysphagia, and you can see that there is this,

1:01

uh, rim-enhancing lesion, centrally necrotic.

1:05

Located at the lateral retropharyngeal space

1:08

and extending into the peripharyngeal space.

1:11

You can see the normal peripharyngeal

1:12

space on the contralateral side here, and

1:15

you can see how small it is on the other side.

1:18

There is mass effect on the mucosal space and the

1:22

oropharynx here, and this is the torus tubarius.

1:26

This is the fossula supramandibularis.

1:28

You can see how there's mass

1:29

effect from that lesion as well.

1:32

Now, the reason, and I just have the component or

1:36

the associated PET CT image for you to see that

1:40

it was abnormally metabolically active, right?

1:43

Um, so the reason I wanted to

1:46

discuss this area of the, um,

1:51

of the, um, suprahyoid neck, um,

1:54

is that it is an area that is very

1:56

difficult for clinicians to see.

1:58

So just a little bit of history

2:00

on the name of the node of Rubier.

2:01

So Henry Rubier was anatomic

2:04

anatomy professor in France.

2:06

Um, he actually wrote a very extensive

2:08

book on the human lymphatic system and

2:10

all the lymphatic levels that we utilize

2:12

today actually arise from this work.

2:15

And it is due to him that we give it this name.

2:19

So the node of Rubier is located in the lateral,

2:22

um, retropharyngeal space, and it is located

2:25

anterior to the longus colli muscle.

2:28

They extend from the C1, C2 level

2:30

to the level of the hyoid bone.

2:32

As you can see, um, usually the size is very,

2:35

very small, 3 to 5, um, millimeters, and I

2:38

don't know if you caught that we measured

2:40

that, um, node of Rubier, and it was

2:42

2.7 centimeters, so clearly very, very abnormal.

2:47

The reason this is so important to keep in mind

2:51

when you are evaluating head and neck tumors

2:53

in the suprahyoid neck is that these nodes

2:57

are absolutely not detectable, not palpable

2:59

on clinical evaluation, even when they are

3:02

large as the patient that I just showed you.

3:04

And, um, if the clinician doesn't

3:06

know about it, they cannot treat it.

3:08

And it can be a source, um, of course

3:11

of residual tumor, uh, resulting in

3:13

a much worse prognosis for the patient.

3:17

Um, uh, which actually has

3:19

been proven in the literature.

3:20

So if we don't tell the clinicians that this

3:23

node is there, they're not going to treat it.

3:25

And the patient outcome is

3:26

going to be much poorer.

3:29

So, please make sure that you look

3:30

at these nodes in your evaluation.

3:34

So just a brief, um, anatomy review.

3:37

So, um, MRI neck axial T2 weighted sequence.

3:42

We can see that the retropharyngeal space

3:44

is located posterior to the, um, pharynx and

3:48

is here located in this, uh, blue line with our

3:51

longus colli muscles, um, which are located

3:54

posterior to the retropharyngeal space.

3:57

And then we have this fat line here anterior to

4:00

the vertebral body, which is the um, prevertebral

4:04

space and then lateral to the longus colli muscle.

4:07

It's where we have the lateral retropharyngeal

4:09

space where the nodes of Rubier live.

4:12

So I want you to see that if you have

4:16

a big mass here, right, located in the

4:18

lateral pharyngeal space, that's going to

4:19

move the longus colli muscles posteriorly.

4:24

And that's an indication that you know,

4:27

also you have a lesion in this space.

4:30

Now, um, this has nothing to do with the nodes

4:33

of Rubier, but the longus colli muscles are

4:35

very important in this region of the neck.

4:37

If they're, uh, uh, you know, displaced

4:40

posteriorly, then you must have a mass

4:41

anteriorly in the retropharyngeal space.

4:44

If the muscles are moved anteriorly, then you

4:47

must have a lesion in the prevertebral space.

4:50

Um, so the longus colli muscles are a great

4:54

anatomical marker for location of lesions

4:56

within, uh, the neck, uh, deep spaces.

5:02

So the retropharyngeal space, um, as I

5:06

mentioned already, you must evaluate the

5:07

longus colli muscles to know, uh, where

5:10

the, um, lesions are located.

5:13

Uh, know that the retropharyngeal

5:15

space spans from the base of the

5:17

skull base to the mediastinum.

5:20

Um.

5:21

As we have mentioned already, it is

5:22

anterior to the prevertebral muscles and

5:24

posterior to the pharynx and esophagus.

5:27

And this is also important to understand

5:28

that it's not a single space; it's actually

5:30

a double space with two components.

5:33

The true retropharyngeal

5:34

space and the danger space.

5:36

And so this is what we're talking about, okay?

5:38

So you have the anterior retropharyngeal

5:41

space, which terminates at C7.

5:44

Uh, this space will not extend

5:46

into the mediastinum and will

5:47

not result in um, mediastinitis.

5:50

Whereas the danger space is posterior

5:52

to the, uh, retropharyngeal space altogether.

5:56

It extends past the C7 vertebral body into

5:59

the mediastinum and can cause, uh, severe

6:01

mediastinitis and other, uh, problems.

6:03

So this is also a, um, source of

6:06

spread of, um, metastatic disease.

6:08

So notice the Rubier nodes.

6:10

What happens with the longus colli muscles?

6:16

Okay, good.

6:16

So most of you got the, uh, correct answer,

6:19

which is that they're displaced posteriorly.