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Hello, and welcome to Noon Conference hosted by Modality.

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Noon Conference connects the global radiology community through free live

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educational webinars that are accessible for all, and it's an opportunity to learn

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alongside top radiologists from around the world.

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Today, we are honored to welcome back Dr.

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Suresh Mukerji for a lecture entitled Anatomy and Pathology of the

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Nasopharynx. Dr. Mukerji received his undergraduate

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degree from Duke University and his MD degree from Georgetown

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University. He currently holds appointments at multiple academic

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institutions and is a devoted educator who has been an invited speaker

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on over five hundred occasions and written and edited fifteen

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textbooks. We are especially grateful for his support of Modality and

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for serving as our head and neck neuroradiology advisor.

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At the end of the lecture, please join him in a Q&A session where he will address

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questions you may have on today's topic.

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Please remember to use the Q&A feature to submit your questions so we can get to as

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many as we can before our time is up.

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With that, we're ready to begin today's lecture. Dr.

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Mukerji, please take it from here.

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Great. All right. Thanks a lot, Ashley. Uh, thanks again for inviting me back.

1:07

It's, it's always great to be here.

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Um, we do have t- I will make time for questions.

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That's sort of why we moved this up to eleven.

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Um, I do have something to go to at, one o'clock my time, but,

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we moved it up just to just take the Q&A 'cause

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sometimes, I, I certainly always enjoy that.

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So what I'm gonna be doing over the next, hour or so

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is, talking about anatomy and pathology

1:32

of the nasopharynx. And so what-- the outline of this talk is

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that we're first gonna talk about the anatomy of the nasopharynx, and then what

1:40

we'll do is talk about neoplasms, then some infectious and

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inflammatory processes, and then just really one slide on

1:48

congenital and developmental lesions with the understanding that there is

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more of this, and this could be a future topic, as well to,

1:55

to, to come back. So let's, first begin with the

1:59

anatomy of the nasopharynx. So the

2:03

nasopharynx is it's an interesting area because even

2:07

right now there's actually a debate regarding where the

2:10

nasopharynx is, if you will. So

2:13

the anterior portion of the nasopharynx is located behind

2:17

the nasal cavity. So you have these areas right here, which are called the

2:21

choana. So this is the posterior portion of the nasal cavity.

2:25

So the anterior portion of the nasopharynx, which is essentially

2:28

a box, is gonna be delimited anteriorly by the choana.

2:33

Posteriorly, the posterior portion of the nasopharynx is formed by the

2:37

posterior pharyngeal wall. So when we look at this image right here, here's

2:41

our posterior pharyngeal wall. The superior surface of the nasal

2:44

cavity-- excuse me, of the nasopharynx is formed by the skull base,

2:49

and then the lateral margins are gonna be formed by the lateral wall of the

2:52

nasopharynx. Now, what I specifically did is

2:56

I left out the inferior border of the nasopharynx.

2:59

And, and the reason is, is that I don't wanna say there's necessarily debate, but

3:03

you'll find different definitions.

3:05

So back when I was a resident, and I still sort of ascribe to this,

3:09

the inferior portion of the nasopharynx is

3:13

oftentimes approximated by a plane of the hard palate

3:17

going posteriorly to the posterior pharyngeal wall, which is

3:21

located at a ridge right here called Passavant's Ridge.

3:25

But on the other hand, when you look at the different specific,

3:29

definitions in the nasopharynx, the other

3:32

definition that's giving is the superior surface of the soft

3:36

palate. So when you're looking at some anatomic illustrations,

3:40

you'll see the, the n- inferior portion of the nasopharynx extend all the way

3:44

down here because this is the superior surface of the soft palate.

3:48

But on the other hand, you'll also hear it approximated by Passavant's Ridge.

3:52

So the challenge that you get into is that why do you have this

3:56

discrepancy? And the reason is, is because the soft

4:00

palate and the nasopharynx are dynamic structures.

4:03

So for instance, when-- if you swallow, part of the

4:07

function of the soft palate is to prevent your food from going up into your

4:11

nasal cavity. So how do you shut that down?

4:14

Well, what ends up happening is the soft palate contracts and

4:17

extends, and it abuts the posterior pharyngeal

4:20

wall at Passavant's Ridge, which is approximately the

4:24

level of the hard palate coming over.

4:27

And when it actually abuts the posterior pharyngeal wall, well, all of a sudden

4:31

this superior surface is a little bit higher.

4:34

So there is a bit of a, a debate or controversy as opposed to

4:38

where the nasopharynx ends. And the way that I reconcile it

4:42

is that it-- the reason is it's a be-- because it's a dynamic

4:45

structure. So the next thing that I wanted to

4:49

talk about regarding the nasopharynx is

4:53

why do we have a nasopharynx? Sometimes when I start talking about anatomy, the

4:57

first question I kinda ask myself is, you know, over

5:01

development, why do humans and some animals have a

5:04

nasopharynx? So it's a kind of a strange question to ask, but I would say

5:08

if you kind of understand that, it helps better understand the

5:12

anatomy. So when we b- breathe

5:16

in and out, the air comes into our nasal cavity, and basically it

5:20

extends into the nasopharynx, which is a little chamber right here.

5:23

So that's our chamber. Now, the nasopharynx does have a couple of

5:27

important structures. First of all, it separates the air wave

5:31

from the food passage. So if we were-- You know, when you eat, it comes through the

5:35

oral cavity, but when you breathe, it comes through the nasal cavity, and then it

5:39

extends into the nasopharynx. And eventually, it does extend

5:42

inferiorly along the posterior pharynx into eventually the

5:46

trachea and the lungs. So number one, it provides a

5:49

separation. But number two, and an important part of the

5:52

nasopharynx, is that it is attached to a tube

5:56

right here, which runs from the lateral aspect of the

6:00

nasopharynx throughThis eustachian tube

6:04

all the way into the middle ear cavity

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So part of the function of the nasopharynx is to

6:10

provide air that flows through the eustachian tube and

6:14

eventually results in aeration of the middle ear cavity and

6:18

also aeration of the mastoid air cells.

6:21

So if we didn't have a nasopharynx and we didn't have air in that

6:25

chamber,

6:26

then all of a sudden our middle ear wouldn't develop, we'd probably be

6:30

deaf, and also we'd probably be prone to a bunch of

6:33

infections involving our ear because the mastoid air cells are not

6:37

developed. So part of the importance of the

6:40

nasopharynx is that it, it has to stay open.

6:43

It's not like it closes and opens. It's like when you breathe, your

6:47

lungs kinda contract. They, they get smaller, and then they open up

6:51

again. So because this air chamber needs to stay

6:55

open, the anatomy of the

6:58

nasopharynx s- is created such

7:01

that this area has to be opened, and the main

7:05

fascial layer right here that, if you will, that the nasopharynx attaches

7:09

to or is deep to is something called the pharyngobasar

7:13

fascia. So when you look at this black line right here,

7:17

this pharyngobasar fascia forms a lateral margin

7:21

of the nasopharynx, and it's very tough, and it's very thick, and this

7:25

extends superiorly up to the skull base.

7:28

So as a result, this thick fascial layer prevents the

7:32

opening and closing of the nasopharynx as you breathe.

7:35

If you, if it d- wasn't there, then we would have closure and opening of the

7:39

nasopharynx, and we really would have a hard time not only breathing but

7:43

aerating our middle ear cavity. So what are the

7:47

internal contents of the nasopharynx?

7:50

Well, the normal surface anatomy is that you have this little bump

7:54

right here, which we call the torus tubarius, and then anterior

7:58

to this is where this eustachian tube ends up opening.

8:01

So anterior to the torus tubarius is the opening of the eustachian

8:05

tube, and then posterior to this is the famous

8:08

fossa, and that's the fossa of Rosenmüller.

8:11

So when we talk about the fossa of Rosenmüller, the other name

8:15

is called the lateral pharyngeal recess, and this is where squamous cell

8:19

carcinomas are most likely felt to arise from, and we'll

8:23

discuss that in detail. Now, once we go over and

8:27

we look at this image right here, which is an axial T1 weighted

8:30

image with contrast, we can see some really great anatomy.

8:34

So this bump right here is gonna be the torus tubarius.

8:38

This triangular opening anterior to this is the eustachian tube, and

8:42

this area back here is gonna be the fossa of Rosenmüller.

8:46

Now, that's sort of anatomy 101. That's what we kind of describe as a

8:49

normal surface anatomy. But remember, when we talk about the anatomy of the

8:53

nasopharynx, there's a lot more anatomy that we need to discuss.

8:57

So I talked about the pharyngobasar fascia.

9:00

That's that thick black line. Well, when you do your imaging study just

9:04

right, you can actually see the pharyngobasar fascia.

9:07

Here it is on the left, and there's the pharyngobasar fascia on the

9:11

right. Now, if you follow this black line, notice this

9:15

black line right here ends. It's discontinuous.

9:18

And when you see something right here, this discontinuity of the black line, and

9:22

now you have this little muscle right here, well, this is

9:26

actually a natural opening in the pharyngobasar fascia,

9:30

and that natural opening is called the sinus of Morgagni.

9:34

And what's the function of the sinus of Morgagni?

9:38

Well, this defect in the pharyngobasar fascia

9:41

allows our eustachian tube to extend from the lateral

9:45

pharyngeal wall back here to the middle ear cavity.

9:49

Because if we didn't have that opening, there's no way for the eustachian tube to

9:52

get back there.

9:54

This sinus of Morgagni also contains one, and

9:58

some anatomy t- textbooks will say two, it's a little bit variable, but it

10:02

contains two of what we learned were the Italian muscles in medical

10:06

school. They were the levator veli palatini and the tensor

10:10

veli palatini. So when we're looking at the torus

10:13

tubarius, there's a muscle right here which pierces

10:17

the sinus of Morgagni, and, and that's the levator veli

10:20

palatini. And this levav- levator veli

10:24

palatini extends from the skull base and eventually goes down to

10:28

the soft palate, and that elevates the soft palate.

10:32

And there's another muscle that's called the tensor veli palatini, and

10:36

that muscle is a little bit harder to see, and it's more lateral.

10:39

So this is an example of the tensor veli palatini, and this is more lateral,

10:43

and what this does, it tenses the soft

10:46

palate. Now, also within the sinus Mor- of Morgagni are the

10:50

palatine artery and a branch of the pharyngeal artery.

10:54

But basically, that's the anatomy of the nasopharynx.

10:57

So remember, the torus tubarius opening the eustachian tube, fossa of

11:00

Rosenmüller, and this sinus of Morgagni acts to

11:04

allow these normal structures to extend into the

11:06

nasopharynx. But also, when we start talking about

11:10

nasopharyngeal carcinomas as they extend laterally,

11:14

this natural defect in the pharyngobasar fascia acts

11:18

as a natural conduit for early spread of nasopharyngeal

11:22

carcinoma into the surrounding space, which is gonna be

11:26

the parapharyngeal space. So

11:30

what we've done right now is that we just finished going over a pretty

11:34

deep dive into the anatomy of the nasopharynx.

11:37

Now what we're gonna do is discuss some of the neoplasms,

11:42

and the main neoplasm that we're gonna spend the majority of our time

11:45

talking about is nasopharyngeal carcinoma.

11:49

So nasopharyngeal carcinoma is the most common tumor to involve the

11:53

nasopharynx. It's endemic in certain areas of the

11:56

world, so it has a propensity to be

12:00

higher in areas of Southeast Asia.

12:03

So here we can see China, Indonesia, so on and so forth.

12:06

It has a propensity to be in the Middle East, which we see

12:10

here, and then also in Africa as well,

12:13

too.Now, these areas where they have a higher

12:17

incidence of nasopharyngeal carcinoma, there is

12:21

an association, the primary association is with Epstein-Barr

12:25

virus. So Epstein-Barr virus is now a specific

12:28

biomarker that's highly associated with nasopharyngeal

12:32

carcinoma, and then when we look at the Epstein-Barr associated

12:35

nasopharyngeal carcinomas, we can see it pretty well maps

12:39

out here to Southeast Asia, again, Northern Africa, also

12:43

the Middle East. We can also see a higher incidence for some reason in Greenland.

12:47

I haven't figured that out. And in the United States, there is a higher

12:51

incidence in this area right here in Alaska, and that's

12:54

oftentimes associated with the Inuit Indians.

12:57

So for some reason, they have a higher incidence of, of Epstein-Barr

13:01

nasopharyngeal cancer. Now, there are other

13:04

etiologic factors that have been associated with this.

13:07

Some people feel it's due to early exposure to salted fish.

13:11

It's been attributed to some of the aflatoxins that can cause some

13:15

type of, injury, if you will, to the

13:19

mucosa. There's also a higher associated with s- ah, smoking,

13:23

alcohol, and like anything else, there are genetic

13:26

predispositions.

13:29

So when we look at the different histology of

13:32

nasopharyngeal carcinoma, this also varies as

13:36

well. So there is a specific type

13:40

of squamous cell carcinomas that is seen in the United States,

13:44

and this is the keratinizing squamous cell carcinoma.

13:48

But when you look at globally, over the world, this is really somewhat

13:52

unusual. This is one that's more typically seen in the U.S., the

13:55

keratinizing squamous cell carcinoma.

13:58

But the most common type of nasopharyngeal carcinoma is the

14:02

WHO type II, and this is the non-keratinizing

14:06

squamous cell carcinoma. And if this non-keratinizing

14:10

squamous cell carcinoma, if it's undifferentiated, it's

14:13

associated with Epstein-Barr virus.

14:16

But on the other hand, if it's differentiated and non, nan,

14:20

non-keratinizing, then that's associated with human

14:22

papillomavirus. So just like in oropharynx cancers, there's an

14:26

associated with HPV, there are some type of

14:30

nasopharyngeal carcinomas that are also associated with

14:33

HPV, but again, the main association really is

14:37

Epstein-Barr virus. And then there's this very rare type right

14:41

here. This rare type right here is the basaloid form,

14:45

and this is WHO type III, and again, this is felt to be really rare.

14:49

But the bottom line is the most common thing is gonna be the EBV.

14:52

It's non-keratinizing, undifferentiated.

14:55

Non-keratinizing differentiated is HPV, and the

14:59

keratinizing one is what we oftentimes see here in the United

15:02

States. So when we talk about

15:06

nasopharyngeal carcinoma, how do these patients usually

15:09

present? Well, they typically present with neck masses, with

15:13

trismus, with otitis media, and cranial nerve

15:16

palsies. And as we step through the different types

15:20

of spread patterns for nasopharyngeal carcinomas, then

15:24

you'll be able to see why these patients present with that.

15:28

So briefly, you know, when you present with a neck mass, it's usually from

15:31

metastatic lymph nodes. When it's trismus, it's usually

15:34

involving the masticator space, and we'll see what that's all

15:38

about. They can present with otitis media and cranial nerve

15:42

palsies, and this is typically due to skull base invasion

15:46

or intracranial extension.

15:49

So what we're gonna do now is that we're going to

15:52

review the new AJCC staging

15:56

system. So the AJCC staging system just

15:59

came out with their ninth version, and the nasopharyngeal one

16:03

was, was released probably about six months ago.

16:07

So I was on the AJC system from five to the eighth

16:11

edition. I, I got rotated off on the ninth, but I s- still, still k- keep

16:15

in pretty close contact with many of the members.

16:18

So what I wanna do now is basically go through the

16:22

different types of spread patterns, go through the staging, but

16:26

also emphasize is that what we say on imaging

16:30

really directly affects how these patients are staged,

16:34

which affects the prognosis and affects also the treatment.

16:38

So the T1 lesions are confined to either the

16:42

nasopharynx or the oropharynx. So on this axial

16:45

images, what we're saying here is that we're looking at this type of spread pattern

16:50

where the nasopharyngeal carcinoma is really limited to the

16:53

nasopharynx. So if I draw a line in the middle r- down,

16:57

down the middle here, this y- yellow arrow points at a tumor

17:01

involving the fossa of Rosenmüller.

17:04

So this is a radiological correlation to this

17:08

schematic illustration, and notice that it's pushing the

17:12

torus tubarius anteriorly. Now, remember what lives in front of the

17:16

torus tubarius? Well, that's the opening of the eustachian tube.

17:19

This opening of the eustachian tube runs all the way back, remember, into the

17:22

middle ear cavity. So in this case, this tumor is

17:26

anteriorly displacing the torus tubarius, so it's

17:30

occluding the eustachian tube, and as a result, what you end up

17:34

having is a serous otitis media. So here's mucosal

17:38

thickening involving the mastoid air cells, and you can also get it

17:41

involving the middle ear. So as a result, that's why some of these

17:45

patients with nasopharyngeal carcinoma present with

17:50

hearing loss, because sometimes that fluid will result in a conductive hearing

17:54

loss. Now, when you are reading out the brain MRs,

17:58

remember a lot of things can give you headaches.

18:00

You know, brain tumors can give you headaches, infections can give you

18:04

headaches. My wife tells me spouses can give you headaches.

18:07

A lot of things can give you headaches.

18:09

But remember, once you're looking below the brain, just remember

18:13

that tumors below the skull base can also result

18:17

in pathologies that can give you headaches.

18:19

So in this case, the serous otitis media can give you headaches as

18:23

well, tooSo when we look at the, at sagittal

18:27

reconstructions, what we did again was looking at this extension into the

18:31

nasopharynx and also this extension that's going down to

18:34

approximately the level of the nasopharynx, but also the

18:38

oropharynx as well, too. Now, this is

18:42

another example of a nasopharyngeal carcinoma that's stage

18:46

one. Now we're looking at this anterior extension.

18:49

So the new AJCC system, and they clarified this, is that

18:53

if these tumors extend into the nasal cavity, this is

18:57

also considered a T1 lesion. So basically, we're looking at this

19:01

inferior spread pattern and this anterior spread

19:04

pattern. So the T2 lesions,

19:07

again, it's really based on what we say on imaging,

19:11

and what the T2 types are... So sorry about that.

19:15

What the T2 types are is that, number one, if this

19:18

tumor extends outside of the

19:21

nasopharynx, and if you look at this schematic illustration, it

19:25

extends into the space that's next to the pharynx, the

19:29

nasopharynx, and that's the parapharyngeal space.

19:32

As I mentioned before, there's a little fascial layer, the pharyngobasar

19:36

fascia, that has a sinus of Morgagni, and it's felt that

19:40

that's the initial area where these tumors extend into the, into the

19:44

parapharyngeal space. So if I draw a line down the middle here, compare

19:48

the left side to the right side, the white arrow identifies a very nice

19:52

parapharyngeal space, but on this side, we can see this

19:55

tumor is now involving the parapharyngeal space.

19:58

And again, this is all clinically occult.

20:01

This is what we provide based on imaging, so the staging really is based on the

20:05

radiology. The other thing that can upstage this to

20:09

a T2 lesion is that if you have extension, but this

20:13

extension involves the prevertebral muscle, so not the bone, but

20:17

the prevertebral muscles. So this is an example of a nasopharyngeal

20:21

carcinoma. Here in white is one longus colli

20:25

muscle, and notice on the right side, this tumor has extended

20:28

posteriorly and is now replacing the right-sided

20:32

longus colli muscles. So this is, again, example of a

20:35

T2 lesion. So the bottom line is T1s are pretty much

20:39

maintained within the pharyngobasar fascia, but if it ex-

20:43

starts extending out the pharyngobasar fascia and into the

20:47

adjacent soft tissues, well, that's gonna upstage this as a

20:50

T2. Well, what exactly is a

20:54

T3 lesion? Well, in the new

20:56

AJCC, they've clarified exactly what a

21:00

T3 lesion is, and that's involvement of the bony structures.

21:05

But the thing is that the AJCC is specifically saying it is, it

21:09

has to be unequivocal involvement because there

21:12

was some confusion as to what is involvement of a bony

21:16

structure. So what the new system says is that there has to be

21:20

frank erosion of the bone. So in the last system,

21:24

we would talk about sclerosis and maybe some edema involving the

21:28

bone marrow. Now, in the new system, the third edition, they

21:32

specifically say unequivocal involvement.

21:34

So this is an example here of a nasopharyngeal

21:37

carcinoma involving the skull base.

21:39

It can also involve the vertebral bodies as well, too.

21:43

That bone involvement is gonna upstage it to T3.

21:46

So here's an example here of a nasopharyngeal carcinoma with

21:50

unequivocal involvement of the clivus.

21:53

So this clival involvement, if it's limited to clivus, is a

21:56

T3 lesion. The other thing is that given the

22:00

location of the fossa of Rosenmüller, so this

22:04

co- coronal image demonstrates the cartilaginous

22:08

eustachian tube, and then right above the eustachian tube is our

22:12

fossa of Rosenmüller. Notice the roof of the fossa of

22:15

Rosenmüller abuts the skull base.

22:18

So back in anatomy, we learned that this was a clivus, this was the

22:22

petrous bone, and this is the petroclival fissure.

22:25

Right above the petroclival fissure is a little foramen, and that foramen

22:29

is called foramen lacerum. The carotid artery runs in the

22:34

roof of foramen lacerum. So the bottom line is, is

22:37

that the proximity

22:39

of the fossa of, of Rosenmüller predisposes these

22:43

tumors to extend superiorly and erode the

22:47

superior skull base, and this is what we end up seeing

22:50

here. So if I draw a line down the middle, compare the left side to the right

22:54

side, here's our clivus that we just talked about.

22:57

Here's the petrous bone. Here's our petroclival fissure.

23:00

And in this case, we can see a nasopharyngeal carcinoma that

23:04

extended superiorly to erode the petroclival

23:07

fissure. So we can see the right half of the clivus is absent, and

23:11

also the petrous bone is absent as well, too.

23:15

So because there's involvement of the bony structures, this is unequivocal

23:19

involvement upstaging the lesion to a

23:22

T3. Now, this is a non-contrast T1 weighted

23:26

image, and this patient had nasopharyngeal carcinoma, and what I

23:30

want you to notice is that notice the high T1 signal

23:33

involving the fat of the petrous apex is completely

23:37

replaced by tumor. So here on the left-hand side, we can see the

23:41

normal petrous apex. On the right-hand side, we can see extension of

23:45

the tumor extending into the petrous apex.

23:48

So when you have the bone that's replaced

23:52

by an abnormality that has the exact same signal

23:56

characteristics of the tumor, i.e., direct extension of

23:59

tumor, that's considered T3. So remember, if

24:03

it was just edema involving the marrow or if there was

24:07

sclerosis involving the skull base, that's no longer considered

24:10

T3, so there has to be unequivocal extension

24:14

into the skull base.Now, it is

24:18

important that when you are identifying and contouring tumors

24:22

involving the nasopharynx you know, we would like to--

24:25

so many places have just do it on CT, but I do wanna

24:29

caution you because really the best way to do it is on

24:33

MR. So this is an example of a nasopharyngeal carcinoma.

24:37

The bone was felt to be normal, and if you did your contour, it looks

24:41

like this but when we look at the sagittal images, notice

24:45

how there was tumor extending all the way into the

24:47

clivus. So the bottom line is, is that if you are contouring

24:51

based on CT, make sure you look at the bone algorithms, and

24:55

I strongly repr- recommend

24:58

getting skull-based MRs because if you don't do that, you do run

25:02

the risk of geographic misses because MR is better

25:06

than CT for looking for that direct bone

25:09

involvement. Well, what exactly is a

25:12

T4 lesion now? Well, the AJCC again

25:16

identifies what those criteria are.

25:19

So T4 lesions are defined by involvement of the cranial nerves,

25:23

and they can have unequivocal radiological

25:26

involvement. So if you do see things like perineural spread

25:29

unequivocally, again, that's the big word on imaging, that is

25:33

enough to upstage this to a T4. You also wanna look

25:37

for intracranial inv- in- extension, involvement of the

25:41

orbit, lateral pterygoid muscle, hypopharynx,

25:45

and parotid gland. So any of these involvement is gonna

25:49

upstage these lesions to a T4. So here are some

25:52

examples. This is an example of a nasopharyngeal carcinoma

25:56

that extended into the parapharyngeal space, but notice how it's

26:00

growing superiorly. So if I draw a line down the middle, compare the right

26:04

side to the left side, here is normal V3 going

26:08

through foramen ovale, going into the region of the Gasserian

26:11

ganglion. Notice on the right-hand side, this tumor is growing all the

26:15

way up through an expanding foramen ovale and

26:19

then extending, right up to that skull base.

26:22

This type of unequivocal perineural spread is gonna

26:26

upstage this lesion to a T4.

26:29

This is another example of a nasopharyngeal carcinoma that has frank

26:33

erosion of the skull base. Here's Meckel's cave on the left side.

26:36

Here we can see complete involvement of Meckel's cave, and if you look real

26:40

closely, we can see dural enhancement.

26:43

So this is intracranial involvement, so this will upstage the

26:47

lesion to a T4. The other thing is

26:50

involvement of the orbit. So this is a na- patient that had

26:54

nasopharyngeal carcinoma, and now we have tumor that's involving

26:58

the orbital apex. So in this case, it's not necessarily

27:01

involving a nerve or with a lot of intracranial extension, but if the

27:05

tumor extends into the apex of the orbit or any part of the

27:09

orbit, that upstages this as a

27:11

T4. The other criteria for

27:14

T4 is whether or not the tumor extends all the

27:18

way

27:19

through the lateral pterygoid muscle and along the anterior

27:23

surface. So the reason that's important, as I mentioned, some

27:27

patients with nasopharyngeal carcinoma will present with

27:29

trismus. The trismus is due to involvement of the

27:33

masticator space. Now, some of the earlier staging

27:37

systems had said involvement of the masticator space, so there was a

27:41

little bit of confusion as to how much of the masticator space

27:45

needed to be involved. But in the eighth edition, and this carries

27:49

over to the ninth edition, the involvement has to extend all

27:53

the way to the lateral margin of the lateral pterygoid muscle.

27:57

So here's a normal-- here's the masseter muscle here, here's the

28:01

lateral pterygoid muscle around here, so it has to be this involvement

28:05

here of the lateral pterygoid along the anterior lateral surface.

28:09

And then here's an example here of involvement of the parotid

28:13

gland. Now, we tend not to see this a lot in the US.

28:17

Um, I do a once-a-week readout with my colleagues in Tanzania, and we see

28:21

some of the most advanced cases of nasopharyngeal carcinoma.

28:25

So this is one of those rare cases where there's involvement of the parotid

28:29

gland. So on the left hand here is the normal parotid gland on the left

28:32

side, but on the right-hand side, we can see the parotid gland is rep-

28:36

replaced, and it's actually involving the overlying skin.

28:40

So this is an example again of a T4 lesion, and also

28:44

if the tumor extended from the nasopharynx, it extended through the

28:48

oropharynx and involved the hypopharynx as is seen here, this is

28:52

another example of a T4 lesion.

28:56

So that was an updated version of looking at the T

29:00

stage. The AJCC also made,

29:04

clarified some changes about lymph node staging.

29:08

So when we talk about lymph node staging, N0 means that

29:11

there's no tumor, so N0 is no of the regional

29:15

nodes. N1 is where we have unilateral

29:19

cervical involvement, but the size cutoff is six

29:22

centimeters. T- N2 is when you have

29:25

bilateral cervical disease, so it kinda crossed over to the opposite

29:29

side, but notice how all of this nodal

29:32

involvement has to be above the cricoid cartilage.

29:36

If you do have lymph nodes that extend below the cricoid cartilage

29:40

or have something that we call advanced extranodal extension, and

29:44

I'll talk about that, and I'll show some examples, this will upstage

29:48

this to N3 disease. So let's look at some

29:51

examples. Here's an example of a patient that had

29:54

nasopharyngeal carcinoma, but this patient has a

29:57

metastatic lymph node. So this is N1 disease.

30:01

This lymph node is less than six centimeters, it's

30:04

unilateral, and it's above the cricoid cartilage.

30:08

The other criteria for N1 disease is if you have

30:11

metastases involving the retropharyngeal lymph nodes, and

30:15

this can either be unilateral or contralateral.

30:18

And the reason that's the case is that the lymphatics from the nasopharynx have

30:22

cross-connectivity with both the right and the left

30:25

retropharyngeal lymph nodes, so they're very, very easy to be

30:28

involved. So we tend just to classify any

30:32

involvement of the retropharyngeal lymph nodes as

30:35

N1.Now, what's N2 disease? Well, this

30:39

is an example of N2 disease. Here we have bilateral

30:42

metastatic lymph nodes. Here we have on the right side and on the left

30:46

side, and the size of the lymph nodes are less than six

30:49

centimeters. So because these lymph nodes are located above the

30:53

cricoid cartilage, in this case, they happen to be level two lymph nodes, so, so

30:57

they're up here, this is an example of N2 disease, and

31:01

again, that two is involvement of the bilateral lymph

31:05

nodes.

31:06

And this is an example of N3 disease.

31:10

So when we look at N3 disease, what we're looking for are lymph

31:14

nodes that are greater than six centimeters, so you have a conglomerated

31:17

group of lymph nodes that are greater than six centimeters, as we see

31:21

here. The other criteria is that if you look

31:25

for lymph nodes that are below the cricoid cartilage, so everything that we

31:29

talked about before was above the cricoid cartilage, but if you have a

31:33

lymph node that's below the cricoid cartilage, then this is

31:37

gonna upstage that disease to N3. And

31:40

the other thing that the AJCC emphasized this year

31:44

was advanced extranodal extension.

31:48

So extranodal extension is where the tumor within the

31:51

lymph node extends outside of the capsule of the lymph node.

31:56

Now, I don't wanna get into... There's a whole big discussion on extranodal

31:59

extension. For nasopharyngeal carcinoma, it was pretty simple.

32:03

It has to be advanced extranodal extension, and that is

32:07

defined by involvement of the adjacent structures.

32:10

In this case, it happens to be the skin.

32:13

We can see involvement of the paraspinal muscles, and in this case, we

32:17

can actually see encasement of the carotid artery.

32:20

I put this slide here in particular because notice how this is above the level

32:24

of the cricoid cartilage, so this is actually a level three lymph node, but if

32:28

you see a level three lymph node that has involvement of these structures,

32:33

you automatically jump all the way down to N3

32:36

disease. So again, it's not N1, N2.

32:39

This is N3 because of that extranodal extension.

32:44

The other point that I wanna make and, is, is that if you do have a

32:47

patient that comes in with an unknown primary, so an unknown

32:51

primary is when a patient presents with metastatic lymph

32:55

nodes. So if you have a metastatic lymph node and you biopsy and

32:59

it comes back as squamous cell carcinoma, the next thing that you

33:03

wanna be able to do is identify the primary

33:06

site. If you cannot identify the primary

33:10

site, well, what we now do is that we take that

33:13

tissue and test for two specific biomarkers, and

33:17

those biomarkers are gonna be HPV and EBV.

33:22

So if the biomarker was positive for HPV, then in

33:26

the new staging systems, we just assume that this is an

33:30

oropharyngeal squamous cell carcinoma because these have a high

33:34

association with HPV. But on the other hand, if you

33:37

test for Epstein-Barr virus and it's negative, we assume it's an

33:41

unknown primary. But if you do test for

33:44

A-EBV and it's positive, then we assume that

33:48

this is a nasopharyngeal carcinoma, and this tumor is staged

33:52

as T0 nasopharyngeal carcinoma. So again, for

33:56

unknown primaries, wherever you are in the world, the recommendations

34:00

are is to test specifically for HPV and

34:03

EBV, and if it's EBV positive, we assume it's in the

34:07

nasopharynx. Well, the next thing that...

34:11

Whoops, jumped a little bit ahead.

34:12

The next thing that we're now gonna do is that we're now gonna talk about different

34:16

types of nasopharyngeal tumors. Now, the,

34:20

World Health Organization in their most recent edition scaled

34:24

the number of tumors that arise in the nasopharynx down a

34:28

lot. But having said that, we know that there are a lot more.

34:32

There are three or four tumors that can involve the nasopharynx.

34:35

So what I'm gonna do is that we already talked about nasopharyngeal

34:39

carcinomas. There are a lot of tumors that can involve the

34:42

nasopharynx, but what I wanna do is kind of give you

34:47

kind of a practical approach and then also identify

34:51

specific imaging findings that can allow you to make the

34:54

diagnosis, because a lot of these imaging findings for these tumors are

34:58

nonspecific. And what even makes it more complicated now in

35:02

two thousand and twenty-six, a lot of the tumors that we were

35:06

calling based on histology are now transitioning their

35:10

names to the specific genetic mutation, so there's a lot of transition

35:14

going on. But what I'm gonna do is go over some of the classic

35:18

imaging findings and kind of give you an approach for nasopharyngeal

35:21

carcinoma. So here's an example of a patient that presents with

35:25

right-sided, ear pain and otalgia and hearing

35:29

loss, and if you draw a line down the middle, notice the yellow arrow

35:33

right here looks at loss of the normal surface

35:36

anatomy. So here's the normal torus tubarius.

35:39

There's the opening to the eustachian tube.

35:40

You can see all of that's obliterated on the right.

35:43

This is an example of a non-contrast T1, and there's the

35:47

contrast-enhanced T1-weighted image.

35:49

And if you look real closely, there's actually abnormal tumor right

35:53

here, which in this case is surrounding the torus tubarius

35:57

and the opening to the eustachian tube, and again, just compare it to the opposite

36:00

side. But one thing that you should always do when you look at this is that we

36:04

talked about tumors that arising in the nasopharynx.

36:08

Remember, the nasopharynx inferiorly is contiguous with the

36:12

oropharynx. So on some occasions, what you can have

36:16

are soft palate tumors that spread superiorly to

36:19

involve the nasopharynx. So this was actually example of a

36:23

right-sided oropharynx cancer that involved the tonsil.

36:27

It extended superiorly to the level of the soft palate and then

36:31

grew up to involve the nasopharynx.

36:33

This type of spread is oftentimes clinically occult, so it's

36:37

really up to us to identify the type of spread,

36:41

and also, we can also be helpful to identify where the tumor's arising

36:45

from. So in this case, it's superior spread of a tonsil

36:49

cancer. If you're not sure, you can also test for

36:53

HPV or EBV. If it's HPV positive, it's

36:56

probably gonna be oropharynx. If it's EBV positive, it's

37:00

probably gonna be nasopharynx.So here's

37:04

another tumor that can involve the nasopharynx.

37:08

And the reason that you can get lymphomas involving the

37:11

nasopharynx is in part because of this person.

37:15

This is Waldeyer Hartz, and you probably have heard of Waldeyer Hartz

37:18

because of his famous anatomic ring, and that's called

37:22

Waldeyer's ring. So what Waldeyer's ring is a

37:26

ring of lymphoid tissue. The inferior

37:30

portion forms the lingual tonsils, the lateral

37:33

portion forms the palatine tonsils, and superiorly you

37:37

have this type of adenoidal tissue that involves the

37:40

nasopharynx. So this is an example of a tumor,

37:44

involving the nasopharynx. This is lymphoma, and you can see it

37:48

has a very, very bland appearance.

37:50

So if you are a betting person, you'd probably say squamous cell carcinoma,

37:53

number one; lymphoma, number two.

37:56

But what are some tricks that can help you make the diagnosis that this is

38:00

lymphoma? Remember, lymphoma is a

38:03

lymphoproliferative/hematopoietic

38:06

disorder. So as a result, because of the

38:10

origin of a lot of the, the, our, our blood, it comes from our

38:14

bone marrow. So this was a case that I saw years ago

38:18

in the middle of the night where I saw this mass involving the sphenoid sinus, but

38:22

notice this clivus is completely replaced.

38:25

This was an older patient, about fifty-five or sixty.

38:28

The clivus should be white. So when I see a

38:31

tumor and there it's associated with replacement

38:35

of the marrow, then I start thinking about lymphoma.

38:39

And this is another example of a tip-off of lymphoma.

38:42

Here we see lots of enlarged lymph nodes.

38:45

This is a nice example of lymphoma.

38:48

So if I see something like this, and I see sort of these big cannonball

38:52

lesions, and lymphoma tends not to enhance as much as squamous

38:56

cell carcinoma. So if I see these big cannonball lesions, then I can

39:00

suggest that the lesion that we're actually seeing here is due to

39:03

lymphoma as opposed to squamous cell

39:06

carcinoma. Well, here's another type of tumor

39:10

that can involve the nasopharynx.

39:12

So here the yellow arrow points at a mass involving the nasopharynx, and

39:16

if you look real closely, it's extending into the

39:19

parapharyngeal space. Now, what kind of tips you off

39:23

on this one is that, again, if you draw a line down the middle, compare the

39:27

right side to the left side, first of all, there's that mucosal thickening

39:31

involving the mastoid air cells, so it's obstructing the eustachian tube.

39:35

But what I want to point out on the right side is this oval structure.

39:38

This is the third division of the fifth cranial nerve.

39:41

This is V3, and it's located medial to the

39:45

lateral pterygoid muscle. So in this case, this

39:48

relatively low volume tumor has crawled into the

39:52

parapharyngeal space, but it's jumping on V3 and

39:56

going all the way through foramen ovale into the region

40:00

of Meckel's cave and the Gasserian ganglion.

40:03

So the point is, is that if you have a relatively low volume tumor like

40:07

this, and it has a propensity for perineural spread,

40:11

then we can suggest the possibility of a minor salivary gland

40:15

tumor because we have this perineural spread.

40:18

Now, this could still be squamous cell carcinoma, there's no doubt,

40:22

but at least in my experience, by the time SCCA tends to involve the

40:26

nerve and extend intracranially, it's a little bit more advanced.

40:29

So if I see this, then I start thinking about minor salivary

40:32

gland tumors, and these types, adenoid cystic,

40:36

mucoepidermoid, and some types of adenocarcinomas, are

40:40

really the most common ones that are associated with perineural spread.

40:43

So I found this to be helpful, as well

40:47

too. Now, this is an example of a patient--

40:51

of tumors involving the nasopharynx.

40:53

This is a slower volume, this is a larger volume, and this is a large

40:57

volume. There's no way really, I think, you could make this

41:01

on the imaging findings alone. But if I told you that this was a

41:04

child, then we can make the diagnosis of

41:07

rhabdomyosarcoma. So we know that

41:10

rhabdomyosarcomas are the most common soft tissue sarcoma

41:14

in children, and typically they present when less than two

41:18

years old. Now, there are different types of histology.

41:22

You know, we as radiologists, we love to try to guess the

41:24

histology. In general, I kind of leave it up to the pathologist

41:29

because really it's up to the surgeon to biopsy it and the pathologist to perform

41:32

the analysis. But in general, if it's embryonal, so

41:36

embryonal meaning young, this is associated with younger

41:39

children. If it's alveolar, this is more associated with older

41:43

chist-- children and young ad-adults, and P,

41:46

pleomorphic, is more associated in adults.

41:49

So I just kind of remember EAP. And there is a spindle

41:52

cell variant, which I really think is nonspecific.

41:56

But the bottom line is, is now there are various genetic

41:59

subtypes, so we are transitioning now to more of a-- from a

42:02

histological assessment to more of a genetic assessment.

42:06

And really, I kind of leave it up to the pathologist to identify what are the

42:09

specific, genetic

42:11

mutations. Now, this is an example of a

42:15

chordoma that's involving the nasopharynx.

42:18

We know that chordomas are notochordal remnants.

42:22

So chordomas involve the vertebral bodies because

42:26

it's the discs that are-- arise from the

42:29

notochordal remnants. So the notochordal remnants give rise to the

42:32

discs, and that's where chordomas arise from.

42:36

Now, because chordomas can arise from the craniocervical junctions,

42:40

they can extend posteriorly, but they can also extend anteriorly

42:44

and present as a nasopharyngeal mass.

42:48

The key thing here is that notice how on the T2 weighted images, the

42:51

chordomas are high T2 signal. So when you look at the

42:55

sagittal images, you may think, "Hey, is it possible this is a large

42:59

cephalocele extending anteriorly?"But it's really not

43:03

because when you give contrast, this thing densely enhances with

43:06

contrast So chordomas have a classic imaging

43:10

appearance. They tend to be high signal on T2 and then

43:14

enhance with contrast. So it almost gives us a

43:17

pseudocystic

43:19

C-Y-S-T-I-C appearance And the reason why that's

43:23

the case is because the characteristic cell associated

43:27

with a chordoma is the fissurifera cell and this

43:31

contains mucin and glycogen. So even though it is

43:34

solid, it does have signal characteristics that's gonna

43:38

give us high signal on T2. So this is just the

43:42

classical appearance of a chordoma and remember the classic imaging appearance,

43:46

your midline high T2 signal, and they can extend

43:49

anteriorly into the nasopharynx.

43:53

Well, the next thing that we'll do is discuss some infectious and inflammatory

43:57

processes. The first thing that we'll do is talk about probably one of the

44:01

most common things that you'll see in your practice, especially in kids,

44:05

and that is the presence of just adenoidal hypertrophy.

44:09

As I mentioned earlier, you can have adenoidal tissue involving

44:13

the nasopharynx as we see here. This is the superior portion of

44:17

Waldeyer's ring. We're all born with adenoidal tissue in

44:21

the nasopharynx, and usually over time it starts

44:24

to atrophy. So really by the time you're forty or forty-five

44:28

years old, you really shouldn't have any adenoidal tissue at all.

44:32

But especially in younger kids, you can have this hypertrophy of the

44:36

adenoidal tissue. So sometimes the imaging findings are

44:40

nonspecific. I mean, clearly you can have maybe a

44:43

lymphoma that looks exactly like this in a kid, but again, it tends to

44:47

be rare. So what are the things that we look at that reassure

44:51

us that we're just dealing with regular adenoidal hypertrophy?

44:55

Well, the first thing is this, these arrows right here point

44:59

at the pharyngobasar fascia. So notice how this is delimited and

45:03

there's no aggressive extension deep to the pharyngobasar fascia.

45:06

So that's one thing that reassures that it's probably a non-aggressive

45:10

lesion. The second thing is, is that we can have these

45:14

striations, and these are like my favorite, favorite tiger stripes.

45:18

So if you do see the striations within the mass, think of my

45:22

tiger right here. And when you have these tiger stripes, this really is more

45:26

indicative of a benign process. So those are two things that

45:30

I look for that reassure me that I'm just dealing with benign

45:34

adenoidal hypertrophy. Another

45:37

infectious or inflammatory process that can involve the retropharyngeal

45:41

space is that you can have edema involving the

45:44

retropharyngeal space. Now, when we look at the retropharyngeal

45:48

space, the space behind the nasopharynx, we have this fascia, which is the

45:52

alar fascia. This area right here is the true

45:55

retropharyngeal space where we have our retropharyngeal lymph

45:59

nodes. And then behind here is the danger

46:01

space. So this is just an example of retropharyngeal

46:05

space edema, and if you do it just right with a leap of faith, you can see this

46:09

line right here, and that is suggestive of the presence of

46:13

the alar fascia. Well, what gives us retropharyngeal

46:17

space edema, where you can have some infectious or inflammatory

46:21

processes, and occasionally you can have deposition of

46:24

calcium along the longest coli muscle, and this is what we

46:28

call calcific tendonitis. So these patients typically present

46:32

in, in the middle of the night, they present with sore throats or something like

46:35

that, and then we can make the diagnosis with the

46:38

calcifications. But I also wanna point out that at least in

46:42

my experience, the calcific tendonitis has been rare.

46:46

And we will see patients that just present with sore throats

46:50

and we'll see this angioedema. So we always

46:54

have to look for calcific tendonitis. There is no doubt about it.

46:58

But I think probably more commonly than that, at least

47:02

in my experience, is that the angioedema can be

47:05

idiopathic, but it can also be associated with some of

47:09

the hypertensive medications and specifically the

47:13

ACE inhibitors. So when I see, see this edema involving

47:17

the retropharyngeal space, I do wanna look for calcific

47:20

tendonitis, but I always ask the referring

47:23

physicians, is it possible the patient had an anaphylaxis response?

47:27

Do they have any specific allergies?

47:29

And are they on any type of antihypertensive, and

47:33

especially the ACE inhibitors? And if they are, they'll go off those

47:37

inhibitors and the patients oftentimes do well.

47:40

So just remember this edema involving the retropharyngeal

47:43

space can be due more to just calcific tendonitis.

47:49

Now, if you end up having a more aggressive infection

47:52

involving the nasopharynx, this can spread to the

47:56

lymph nodes. So this was a patient that has increased soft tissue in

48:00

the prevertebral space extending into the

48:03

nasopharynx. If this infection initially evolves in

48:07

nasopharynx, it can drain to a retropharyngeal lymph

48:10

node. Once that retropharyngeal lymph node becomes

48:14

involved, it can enlarge and it actually suppurate and

48:17

contain pus. So this is an example of not a

48:21

retropharyngeal space abscess, but this is an example of pus

48:25

in the retropharyngeal lymph node.

48:28

So this is the terminology of suppurative adenitis.

48:31

Why is that important? Because if we say the patient has suppurative

48:35

adenitis and has a stable airway, these patients can be

48:38

treated with aggressive intravenous antibiotics.

48:41

They do not need to be taken to the operating room if we as a

48:45

radiologist are confident in saying that it's in a

48:48

retropharyngeal lymph node. But if this patient such

48:52

as this has suppurative adenitis and it's not treated, then it can

48:56

develop into a formal retropharyngeal space abscesses, and

49:00

these retropharyngeal space abscesses need to be drained.

49:04

If these abscesses are not treated, notice the proximity here

49:08

to the vertebral bodies. These can grow, erode the vertebral

49:12

bodies, and eventually extend posteriorly into the spinal

49:16

canal, and you could end up having an epidural

49:19

abscess. So this is the natural progression from suppurative

49:22

adenitis to retropharyngeal space abscess.

49:25

Here's our retropharyngeal space abscess, and if untreated, it could

49:29

extend posteriorly, develop an osteomyelitis and a

49:33

discitis, and eventually become an epidural

49:36

abscess.Well, this is an example of

49:40

another disease that can involve the nasopharynx.

49:43

So what I first wanna do is talk about a little bit of an infection

49:47

right here involving the external auditory canal this is

49:51

what we typically refer to as otitis externa.

49:54

This is usually seen in, in, in patients that swim a

49:58

lot. If you've ever swam a lot, you can develop this inflammation

50:02

involving the external auditory canal this is usually

50:06

seen at otoscopy. Usually, the mucosa is very, very

50:09

boggy and edematous and the surgeons will treat this with just--

50:13

oftentimes they'll just place a wick.

50:15

They'll place a wick in the external auditory canal with some antibiotics

50:20

but on the other hand, if the otitis externa is very aggressive or

50:24

incompletely treated what can happen is that the otitis

50:28

externa can erode the bone so this is an example of bone

50:32

erosion, and this is what we refer to as malignant otitis

50:35

externa now, what ends up happening here is that in some

50:39

cases this malignant otitis externa erodes the bone

50:44

and remember what's below the skull base.

50:46

Well, what's below the skull base is the nasopharynx.

50:49

So this is an example of a skull-based

50:52

osteomyelitis. So this is skull-based osteomyelitis that

50:56

extended anteriorly to involve the nasopharynx.

50:59

So if I draw a line down the middle and compare the left side to the right side,

51:03

here's the nor-normal ptoris tubarius.

51:05

There's the opening, the eustachian tube.

51:07

Here's the fossa of Rosenmüller. I wanna point your attention

51:11

here to the longus colli muscle and also the signal

51:15

loss here involving the skull base.

51:18

So here we can see abnormal enhancement of the skull base, abnormal

51:21

enhancement of the longus colli muscle.

51:24

This is involving the nasopharynx and extending posteriorly and

51:28

this is another example of a severe skull-based osteomyelitis.

51:31

I literally just saw this about two months ago.

51:34

This is diffuse involvement of the soft tissues involving both ptoris

51:38

tubarius. Unfortunately, this had been smoldering for a couple years and

51:42

was never picked up and eventually we ended up did picking it up, but

51:46

this was actually-- on this image, it was actually not seen initially by

51:50

some, other colleagues and unfortunately this was just an

51:54

advanced case of skull-based osteo.

51:56

So again, it gets to that point that I'm talking about before

52:00

is that when you do have patients that have headaches and fever and they have a

52:03

brain MR, you know, please, please, please, please make sure you look

52:07

below the skull base, which in this case was due to severe

52:11

osteomyelitis.

52:13

So this is, just the natural progression of skull-based

52:16

osteomyelitis. This is an example of otitis

52:20

externa. Notice how it's involving the right temporomandibular

52:24

joint. Once it gets below the temporomandibular joint, it can

52:28

extend anteriorly to involve the carotid space and in this

52:31

case, notice how there's obliteration here of the fat in the

52:35

parapharyngeal space. If this goes on and it's untreated,

52:39

it can extend superiorly to involve the petroclival fissure.

52:43

For all the world, this looks just like nasopharyngeal carcinoma, but these

52:47

patients are typically much sicker and then if it's untreated,

52:51

it can extend all the way intracranially.

52:53

So here's a normal Meckel's cave on the left, and there's Meckel's cave on

52:57

the right, and we can see this inflammatory process has extended

53:01

all the way into the skull base

53:04

and then the last slide I'll show is just a little bit of a teaser.

53:07

We don't have time to talk about congenital and developmental lesions,

53:11

but this was sort of one of the classic things we always show when we give a

53:15

nasopharyngeal talk. So what we have here is a

53:18

submucosal mass that has a high T1 signal

53:22

lesion that's located between the longus colli

53:25

muscles. This area right here between the longus colli

53:29

muscles is what we refer to as the pharyngeal bursa and if you

53:33

see a little mass right here that's high T1 signal, this is the

53:37

classic example of a torn wall cyst.

53:41

Here's an example of a child that presented with a nasopharyngeal

53:45

mass and when we look at it, what we see here is a large

53:49

defect involving the vertebral column.

53:52

So unfortunately, this was a case of a cephalocele, in which case

53:55

the cervical cord extended anteriorly through this defect

53:59

and presented as a nasopharyngeal mass.

54:03

This is another child that presented with a nasal glioma.

54:06

Remember, nasal glioma is, is gli- is brain tissue

54:10

that somehow gets lost, extends inferiorly into

54:14

the nasal cavity, but the communication with the intracranial

54:18

contents is lost. So basically, if you will, you have an

54:21

ectopic area of dysplastic brain that it's not in direct

54:25

communication with the brain. That's why it's not technically a

54:29

cephalocele and because it's separate, we refer to that as

54:33

a nasal glioma.

54:35

This is just an example of a lymphatic malformation, and this is an

54:39

example of a mixed vascular malformation.

54:41

So just realize you can have a lot of developmental or

54:45

congenital lesions involving the nasopharynx as

54:49

well, too. So just one brief slide on congenital and developmental

54:53

lesions. So in summary, what we've done over the last

54:56

fifty-five minutes or so is that we took a deep dive into the

55:00

nasopharynx and we talked about the anatomy and the pathology.

55:03

So specifically, we talked about the anatomy.

55:06

We talked about neoplasms, really talked about nasopharyngeal

55:10

carcinoma and for those of you that are neuroradiologists, I did

55:14

go over the new classification system for the AJCC

55:18

and emphasize how really what we say on imaging

55:22

directly affects staging, which affects treatment, which

55:25

affects prognosis. We talked some about infectious and

55:29

inflammatory processes and then a little bit about congenital

55:33

and developmental lesions. So Ashley, thank you very much and everyone for

55:37

your attention and I'm happy to take any questions you may have.

55:41

Thank you, Dr. Mukerji, for that really great deep dive into this

55:45

area. We will open the floor now for some questions, so if you've

55:49

got one, please go ahead and put it into that Q&A box. And Dr.

55:53

Mukerji, I think we've got a couple in there, if you can open up your

55:56

box.

55:57

We do. Okay, good. Okay.

56:01

Good. Is the box open or are we here...

56:04

Um, which am I using, chat or the more?

56:08

Let's see. The Q&A?

56:09

Um, yes.

56:11

Okay, great. Okay. Okay.

56:15

Okay. Oh, great.

56:18

So the first question's a great question from Matt.

56:20

Um, "Hello, regarding nasopharyngeal lymph node staging and the size of the

56:24

node, less than six me- centimeter, is this mentioned in the axial

56:28

plane or any of the three planes?" So that's a great question.

56:31

So for the six centimeter, it's measured in any plane, so the

56:35

largest dimension. So we do get a little bit...

56:38

It is confusing because when we kind of upstage and we talk about

56:42

metastases, we have a size criteria,

56:46

and that's us- usually 1 to 1.5. That's a talk unto its

56:50

own. But when we are talking about the six centimeter for

56:53

nasopharyngeal carcinoma, it's the largest dimension that you can

56:57

measure. So thanks for that great question.

57:00

Um, "How do we differentiate perineural invasion and perineural

57:04

spread?" Again, from an anonymous attendee.

57:07

That's a great question. So the way to look at it is

57:11

this. Let me see if I can go back. So perineural invasion

57:15

is a histologic diagnosis. Perineural

57:19

spread is spread along, in general, we call it a named

57:23

nerve. Now, I have a little different appearance, take

57:27

on that, but the bottom line is, is that when the pathologists look at

57:31

a tumor, they'll biopsy it, and some of the prognostic

57:35

indicators that they look for are whether or not there's involvement of

57:39

the lymphatics. They'll look for the depth below the bas-

57:42

basement membrane, and they'll also say whether or not there's perineural

57:46

invasion. And if there is evidence of perineural

57:50

invasion, then those tumors are felt to be at higher

57:54

risk for involve-- of lymph node

57:56

metastases, and in many cases, this could be a

58:00

reason to get some type of adjuvant chemotherapy or

58:04

radiation therapy, especially if this was from an oral cavity

58:08

cancer. Perineural spread is spread along a

58:12

named nerve. So I showed an example of spread along the third

58:15

division of the fifth cranial nerve.

58:17

You can have perineural spread along the facial nerve, perineural spread along

58:21

different nerves. So, you know, that could be a talk f- It could be a

58:25

topic for a different talk if there's interest there as

58:28

well. So, "Can we see the

58:31

retropharyngeal's fascia or do we see the pharyngobasilar

58:35

fascia?" So, you know, I think that's a,

58:39

that's a good question. I, I'll, I tell you what about the fascia, okay?

58:43

So this is my kind of approach on the fascia.

58:46

The fascia was described somewhere between the

58:50

late 1700s and the ei- early 1800s, and they

58:54

were described by some amazing French

58:57

anatomists. And again, those were in the late

59:00

1700s. Now, there was an article written in

59:05

1800

59:07

that-- by Malgagni, and one of the things... And I happened to read the article.

59:10

That tells you what kind of boring life I have.

59:13

So I read the article, and he made an interesting quote.

59:16

He said, "The name of the cervical

59:19

fascia changes based on basically who the

59:22

author is." So the names of the fascia have changed over

59:26

time. For me, I tend-- If I can

59:30

go back to... Let me see if I can share my screen here.

59:34

Let me see. Sorry about that. So the way that

59:38

I do this is that th- this fascial layer right here was what I

59:42

referred to as the visceral fascia,

59:45

and this was the name that was given by Gridinski and Holyoke in the

59:49

1940s. This visceral fascia, when it gets up to

59:53

the skull base, it's called the pharyngobasilar fascia.

59:57

So if you wanna use the term visceral fascia or pharyngobasilar

60:00

fascia, it doesn't matter to me. I've seen both terms used.

60:04

And then deep to this is the fascia called the alar fascia, and then deep to

60:08

this is the prevertebral fascia. For me, I have a hard

60:12

time seeing the posterior extent of this fascia on

60:15

imaging. Even I have a hard time seeing the

60:18

pharyngobasilar fascia or the lateral margins on imaging.

60:21

The imaging has to be just perfect.

60:23

You have to have thin sections, and, you have

60:27

to have, the patient has to hold rock solid still.

60:30

So for me, in general, I don't think I can

60:33

confidently say that I see the pharyngobasilar fascia in every study.

60:37

I know it's there, but if I see a really good quality study, then

60:41

yes, I do try to look for it.

60:44

Uh, let's see. Where is the next one there? We are going to Q&A.

60:49

Okay, there we go. Okay. Um,

60:53

yeah, so, "What is your cutoff for node size in suppurative adenitis in

60:57

rep-- in, in recommending medical

61:00

management?" Um, and so that's the first question.

61:04

So again, this is from Paul Ryan. It's a great question.

61:06

Um, you know, Paul, to be honest with you,

61:10

when I look for suppurative adenitis, uh... Let's see.

61:14

You can still see my screen, right, Ashley? Is that right?

61:17

Okay, good. So

61:20

are you there? Yeah?

61:22

Yes.

61:23

Yes. Yes. Okay, perfect. So when I, when I, when I look for suppurative adenitis,

61:26

there is not really a size cutoff. Basically, what we

61:30

do is that this is the normal anatomy of the

61:34

retropharyngeal node, so there's a medial and a lateral

61:37

group, and generally, the group that tends to be more involved is the

61:41

lateral groupSo if we end up

61:45

having a fluid collection that is

61:48

paramidline, then this is indicative of suppur- suppurative

61:52

adenitis. So if I see any collection that has a focal area of low

61:56

attenuation within it then I call that suppurative

61:59

adenitis. Sometimes you'll see a lot of enhancement of the

62:03

lymph node and just a little bit of low attenuation.

62:05

Again, if I see that low attenuation I may just call it early suppurative

62:09

adenitis. What I do is I convey that information to

62:13

the referring physician and if I say that there is suppurative adenitis, and

62:17

again say that the airway's intact or they feel the airway's intact,

62:21

then they'll treat with IV antibiotics.

62:23

So there's not nec-necessarily a size cutoff for

62:26

that. And then, how can you tell

62:30

skull-based neoplasia versus malignant otitis?

62:33

Do you ever do white cell scans? No, tend not to

62:37

do it, but I mean, you are 100% right.

62:41

I mean, sometimes you just-- Sometimes it's hard to

62:44

tell, and I remember, this case right here was looked at

62:48

by one of my really, really smart colleagues and, and

62:52

initially, you know, we weren't sure or, or the person wasn't really sure whether

62:56

it was infectious or not because this patient had had this

63:00

brewing for about six months to a year.

63:04

So in general, sometimes it can be difficult.

63:08

Nine times out of ten, the patients are febrile, they have a lot of throat

63:11

pain, and they have a lot of otalgia, and when the surgeons look in, they

63:15

will see boggy mucosa. So those clinical

63:19

findings can help, but sometimes in patients that cannot elicit

63:23

an immune response, they may not be able to develop the fever, the

63:27

fever's sort of a natural body response to contain an

63:30

infection. So if you do have someone that is somehow

63:33

immunocompromised or immunodepressed, it, it can be, it can be

63:37

difficult. But I would say eighty to ninety percent of the time we're, we're pretty

63:41

sure. And, yeah, thanks for your kind words. Appreciate it.

63:46

Uh, let's see, we talked about perineural spread and perineural...

63:49

So again, perineural invasion we're not gonna see on imaging.

63:53

With the perineural, perineural spread is based on

63:55

imaging. Okay.

63:59

Okay,

64:02

so f- thanks. For, for ENE, the size

64:06

of the nodes or matter or including six centimeters.

64:09

So the thing about extranodal extension, and again

64:13

that is unto a talk, unto its own because r- it's really a

64:17

rapidly evolving area. When we talk about

64:20

nasopharyngeal carcinoma and we talk about

64:24

advanced extranodal extension, again the key word is

64:28

advanced, it, it is invasion of

64:31

adjacent structures. So you can still have a two or

64:35

three-centimeter lymph node, but if it's encased in the carotid

64:38

artery, if it's extending to the skin, if it's invading

64:42

the adjacent muscles, then

64:45

you, you can still have extranodal extension even though the lymph node isn't

64:48

huge. I just kind of showed a, a large one here because the

64:52

larger the lymph node, the greater the likelihood there is

64:56

to have extranodal extension. But yeah, it can occur in smaller

65:00

lymph nodes. So, I, I, I hope that, hope that makes

65:04

sense.

65:06

Um, from Nicholas Paez, "Do you, do you mention

65:10

specific staging in my report?" So yeah, I actually do.

65:14

I think part of it is because I'm biased 'cause I've been, you know, I've been

65:18

working with staging since the eighth edition.

65:20

So I would say this, is that if it's something

65:24

where I am quite sure that the

65:27

radiological findings are unequivocal, then I will mention the

65:31

staging. So for instance, if, if I'm, if I'm in a

65:34

situation, let's just say like

65:37

this where there's just a tumor that's involving

65:40

the Fossa of Rosenmüller with no extension, I'll just say

65:44

it's a T1 lesion. You know, if I see

65:47

unequivocally that there is a only one

65:51

metastatic lymph node on one side, I'll call that

65:54

N1. So if I have a patient that has a, a lesion

65:58

in the, the Fossa of Rosenmüller with only

66:02

one metastatic node on the ipsilateral side, I'll just say it's

66:05

consistent with a staging of T1N1.

66:09

So yeah, I will do this. Now, once it gets a little bit more advanced

66:13

and if you're not sure, then there's no need to do it.

66:15

But quite frankly, I think nasopharyngeal carcinoma is one of the

66:19

easiest ones to stage in your report.

66:22

It gets a little bit more tricky when we get to oral cavity lesions

66:26

because that's oftentimes now based on the involvement of the

66:30

basler- basal membrane, which is a histologic diagnosis.

66:33

But as of now, nasopharyngeal carcinoma really is based on

66:37

imaging, and that's why I spend so much time going over and

66:41

correlating, anatomy imaging and the

66:44

staging.

66:47

Um, "So how to differentiate skull-based

66:50

osteomyelitis versus neurofibromas and schwannoma?"

66:53

Um, I know what you're talking about. Um, sometimes the...

66:57

if you don't have the history, it can be tricky.

67:00

If you have patients that have really, really advanced

67:03

NF1, the NF1 can grow all the way along

67:07

the different nerve fibrils, and that can be really, really hard.

67:11

But in general, clinically it's not hard because

67:15

patients with NF1 typically have classic appearance based

67:19

on the lisch nodules and the subcutaneous bumps from the

67:22

neurofibromas, whereas the skull-based osteomyelitis patients will be

67:26

febrile, oftentimes they're older, and oftentimes they're

67:29

diabetic.

67:32

Um, "How do we appreciate perineural

67:36

spread when MR is not available?" Well, you know, you can

67:40

see it on CT. Um,

67:43

as I mentioned, I have the privilege of reading out with some folks from,

67:47

uh-Um,

67:50

Tanzania and they predominantly do CT and I have noticed you

67:54

can tell, ah, bone-- you can tell perineural spread on

67:57

CT but it has to be more advanced and you have to

68:01

see enlargement of the neural foramen.

68:03

So you can see it, but you cannot pick it up as easy

68:08

as you can on MR. So in advanced cases, you can see

68:11

it.

68:13

Hey, Mike. Um, my friend Mike Ma- Kasitakis is here. Great seeing you, Mike.

68:17

Um, if there is involvement of the alar or prevertebral fascia,

68:21

those cases are not operative. Yeah, yeah, that's exactly right.

68:25

So Mike, I don't know about the alar fascia 'cause it's, um...

68:28

In fact, just yesterday at our head and neck tumor board, we had a patient that had

68:31

a big hypopharynx cancers. Um, the alar fascia, it's

68:35

really, really hard to see but yes, if there is involvement of the

68:39

prevertebral fascia and that typically arises in

68:43

hypopharynx cancers, specifically posterior pharyngeal wall

68:47

cancers, if we say that on imaging, then those

68:50

patients, I would say ninety-nine times out of a hundred now, are not gonna

68:54

be operated on. Those patients are typically treated with chemotherapy and

68:58

radiation therapy. Mike, great to see you.

69:00

Thanks for, for attending. Um,

69:06

so, ah, differentiating lymphoid hyperplasia and lymphoma

69:10

on nasopharynx MR. So I did kind of allude to that.

69:14

Um, I think part of it is based on the age.

69:17

If I see more lymphoid tissue in kids, it's more

69:21

likely just tends to be hypertrophy, but on the other

69:25

hand, if-- I'm gonna show that case I just

69:28

showed. Where is that? Yeah, this one right here.

69:30

But on the other hand, if I see this degree of soft tissue

69:35

in a fifty-five or sixty year old, what I usually say in my

69:38

report

69:40

is I end up saying there's increased soft tissue involving the

69:43

nasopharynx. This could be due to lymphoid

69:47

hypertrophy, but this is more than typically expected at this

69:50

age and then can be correlated with direct

69:54

nasopharyngoscopy. The other thing too that I look for

69:59

is that if I am concerned, I look at the mastoid

70:02

air cells, and if the mastoid air cells are aerated, there's no

70:06

mucosal thickening, that kind of increases my

70:10

confidence that I'm not really dealing with an aggressive

70:13

lesion. But on the other hand, if there is mucosal thickening

70:17

and we have this increased soft tissue in an older patient,

70:21

then my suspicion increases

70:25

and, and I'm a little bit more,

70:28

dogmatic about recommending a

70:31

nasopharyngoscopy.

70:34

Um,

70:35

yeah. How about skull-based osteo without MOE? Yes.

70:38

Certainly you, you can get that, and there are various

70:42

etiologies for it. Sometimes it can be due to direct extension

70:45

from an infection involving the nasopharynx.

70:48

Some of these can be due to patients that are immunocompromised.

70:52

Um, oftentimes it can be due to trauma as well too.

70:56

So yes, you can have a variety of skull-based

70:59

osteomyelitis that without malignant otitis

71:02

externa. I have to admit, in, in my

71:06

"experience" in my practice pattern, I would say the majority of skull-based

71:10

osteo that I see is due to malignant otitis ex-externa, but on the

71:14

other hand, certainly you can have, different effect--

71:18

infections, especially if the patients are,

71:21

immunocompromised or on some type, or

71:24

immunodepressed. Sometimes I use the term immunodepressed because

71:28

sometimes patients are now on low-level

71:31

immunotherapies.

71:34

Um,

71:35

so how about N zero nasopharyngeal carcinoma that... Yes.

71:40

So I believe that's correct. If it's an N ze-zero nasopharyngeal

71:43

carcinoma, the treatment is usually based on the N stage

71:48

because remember the T-TNM is

71:51

primary site, nodes, and metastases.

71:55

The TNM then gets rolled up into an

71:58

overall higher echelon staging system, and

72:02

oftentimes the treatment is based on the higher echelon staging

72:06

system. So if you did have a T zero but

72:10

you only had w-- N one disease, well, that's an early stage.

72:13

But on the other hand, if you were unfortunate and you had a T zero

72:18

but you had multiple bulky lymph nodes with extranodal

72:21

extension that were EBV positive, then that would bump you

72:25

up, up at a higher stage, and then you'd probably get treated, it

72:29

probably would get treated more aggressively.

72:34

Um,

72:37

let's see. How do you recommend a trainee break down the nasopharynx and

72:40

pathology from basics to skull-based osteo to perineural

72:43

spread? That's kind of a tough one to answer.

72:46

Um, what I would probably recommend is, start with the

72:50

anatomy. Uh, once you understand the anatomy, then

72:55

you can then talk about different pathology.

72:57

I'll throw a plug in for the talk I just gave and then also with

73:00

Medallity. Um, I know, we have

73:04

really, really great content that goes over the anatomy, various

73:08

pathology, so on and so forth. So, you know, I have to say

73:12

that that's a big question, but I think that's why we do have great platforms like

73:16

Medallity.

73:18

Um, let's see. Does every case undergo MR or CT, or

73:22

what's your protocol for the first scan?

73:24

So, you know, for me,

73:28

if s- in general, most people undergo a CT

73:31

first. I have to admit that if someone comes in and they

73:35

have, signs and symptoms of nasopharyngeal carcinoma, I

73:39

would like to start off with an MR because I think it's more helpful.

73:43

But on the other hand, MR and CT are really, really complementary.

73:47

So I, I think this one is really based on opinion.

73:50

It's also depending on access, where you, where, where you live.

73:54

Abir, I don't know if you're in, the US or in India.

73:57

Um, and even if you are in India, there are places that have access to a lot

74:01

of advanced imaging and pl- some places that don't.

74:04

Um, so I would probablyMaybe answer your question, say whichever

74:08

one's more convenient initially.

74:10

Um, but if you were asking me, I'd probably, I'd do

74:14

both, but I'd probably prefer to start off with

74:16

MR. Um,

74:21

well, how can you identify retropharyngeal lymph node?

74:24

Yeah, so that's a really good question.

74:25

So back in the old days when, when I trained back in the last

74:28

century, I hate to say that, we were doing

74:32

much more CT than MR, and we actually wrote some initial

74:36

papers on nasal pharynx and our ability to

74:40

accurately detect retropharyngeal lymph nodes.

74:44

So actually you can see retropharyngeal lymph nodes on

74:47

CT, they're just a little bit harder to see.

74:51

And so I don't know if I've got a, a case of that right now, but

74:55

in general, you kind of look at the same location.

74:57

I mean, here's a CT scan here. The retropharyngeal lymph nodes are

75:01

gonna be located just medial to the carotid artery.

75:04

So what I do is I look for a rounded area with

75:07

obliteration of the fat just medial to the carotid artery.

75:11

So as I mentioned, it's much harder to see on CT than it is

75:15

MR, but on the other hand, if you know the anatomy, and I think I

75:19

showed that, anatomy on this slide right here, you know there's a

75:23

medial and the lateral group. What you do is that you just, like,

75:27

where the suppurative adenitis is, like the medial retropharyngeal lymph node is

75:31

gonna be located right about in here.

75:33

So if you know where that is, then you can focus your search.

75:38

So I don't see any more questions, Ashley.

75:41

I assume that-

75:43

I think you got them all.

75:45

Okay.

75:46

You answered like 20 questions in

75:49

15 minutes. That was amazing.

75:51

Okay.

75:53

Hope- hopefully I didn't talk too fast.

75:55

No. No, you did great. Thank you. Thank you so much for, for this presentation and

75:59

for staying on a little extra to answer all these

76:01

questions.

76:03

My pleasure. Thanks for having me. Thanks everyone for attending.

76:08

Absolutely, yes. And thanks for everyone for asking such great questions and

76:11

participating in today's Noom conference.

76:14

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76:17

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76:21

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76:25

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76:29

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76:33

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76:37

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76:39

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