Ultrasound Evaluation of Regional Lymph Nodes as an Extension of the Breast Ultrasound Exam

Introduction

I am Tom Stavros.
I'm a radiologist and a breast imager from Denver, Colorado,
at the Envision Sally Joel Breast Center.
And today I'm gonna talk about sonographic evaluation
and ultrasound guided biopsy of
regional lymph nodes in patients who have suspicious
or malignant breast nodules.

Evaluation of Regional Lymph Nodes

Hello, I'm Tom Ros
and we're gonna talk today about the evaluation
of regional lymph nodes is an extension
of the breast ultrasound examination.
We think it's very important to stage people as much
as possible with ultrasound from the very beginning.
So anytime we have a patient with a suspicious
or a malignant lesion in the breast on ultrasound,
in whom we will do an image guided biopsy,
either a birads four
or five lesion in the a CR birad results on lexicon,
we automatically evaluate the axillary
and in many cases also the internal mammary lymph nodes.
If we see a definitely abnormal lymph node,
we will perform image guided biopsy on that lymph node,
but we do not biopsy sonographic,
normal appearing lymph nodes and we'll talk about why later.

Normal Lymph Node Appearance

Normal lymph nodes look like small kidneys.
They have a hypo echoic cortex.
They are oval in shape in the long axis
and c shaped in the short axis.
The hilum of the lymph node is open.
This is where the arteries
and veins enter the lymph node and leave the lymph node
and where the eent lymphatics leave the lymph node.
The cortex is the hypo coic part
and the combination of the me doula
and the hilum makeup of variable echogenicity.

Anatomical Comparison to Kidneys

Now, even though lymph nodes look identical
to miniature kidneys, there's one thing that's different
and that's that the afferent lymphatics
actually enter the lymph node
through the subcapsular sinuses, the capsule
of the lymph node, and this would be the opposite side
of the lymph node from the hilum.
The afferent lymphatics enter there
and then the lymph flow is through the subcapsular sinusoids
centrally through the cortical sinusoids between the
germinal follicles
and then through the medullary sinusoids
between the medullary cords and sinusoids.
And finally, they exit the lymph node through the hilum,
through the eent lymphatics.

Metastatic Implantation and Hallmark Signs

The importance of understanding this is that metastases tend
to implant in the subcapsular or cortical sinusoids.
So the hallmark of metastatic disease graphically
is thickening of the hypoechoic cortex.

Age-Related Variations in Lymph Nodes

Now there's a variable range of appearances
of normal lymph nodes depending on how much central
fatty atrophy has occurred.
In young patients we're seeing on the left,
the cortex is relatively thick,
the hilum is relatively small
and the hilum tends to be purely hyper coic
because it's mostly consists of the echogenic interfaces
between the medullary cords and medullary sinusoids.
As people age and get repeated infections
and develop atrophy, the hylum begins to become infiltrated
with fat, and so it becomes more hypo coic
or actually iso coic with other fat.
The medulla, which is the hyper coic part, lying just deep
to the hypo coic cortex becomes thinned
and pushed out to the periphery of the lymph node,
and the cortex may also become thin and atrophic.
In very severe cases, we see the largest lymph nodes
of all these lymph nodes can often be
four centimeters in size,
because they've been replaced by so much fat in the hilum,
but the cortex is thin
and even though the lymph node is large, the fact
that the cortex is thin is very reassuring.
The hallmark of metastatic disease is cortical thickening,
so a large lymph node with
fatty replacement in the hilum is of benign lymph node
and we don't have to worry about it.

Patterns of Metastatic Involvement

Now, most metastases implant in the subcortical
or the subcapsular or cortical sinusoids.
Probably the most common place is in the middle
of the cortical sinusoids about halfway into the cortex from
the periphery to the center.
And then they implant and they enlarge
and as a result, they cause focal cortical thickening
of the lymph node, a focal thickening
of the hypo coic cortex of the lymph node,
which we're showing right here.
This is an example of a classical metastatic lymph node.
The yellow line outlines the normal thickness
of the cord cortex,
and we can see
that there's a focal cortical thickening bulging
outward and inward.
When this cortical thickening becomes more extensive,
it can involve the entire lymph node
and then you can develop uniform cortical thickening.
As I'm illustrating on the right,
this is an abnormal lymph node,
but unfortunately we don't know whether it's a benign
reactive lymph node
or whether it's a lymph node completely replaced
with metastasis.
We need tiebreakers to make this distinction
and we'll talk about how we use tiebreakers later on
to distinguish reactive from metastatic lymph nodes.

Configuration Based on Implantation Site

The configuration and appearance
of the morphologically abnormal lymph node really depends on
where the implantation site of the metastasis occurs.
If the implantation site is in the subcapsular sinusoid
or in the cortical sinusoids toward the outside
or periphery of the lymph node, we'll tend
to see a focal outward
bulge of the cortex.
That looks like a Mickey mouse here.
So on the left now we're illustrating what the normal shape
of a lymph node would be,
and you can clearly see that we have sort
of a Mickey mouse ear bulge outward of the cortex.
This is simply a manifestation of a metastasis
that is implanted more toward the outside of the cortex
or in the subcapsular sinusoid.
Just another example of an outward bulge of the cortex,
because the implantation side of the metastasis
was toward the outside
of the cortex rather than the central or inside portion.
On the other hand, if the implantation site
is more toward the medullary side of the cortex,
we can get a focal bulge inward of the hypo cortex
that can create what we would call a rat bite indentation
of the echogenic hilum.
So in this case, the yellow line outlines
where the normal outline of the lymph node would be,
and we can see that we have a large rat bite indentation
of the hilum by this metastasis
that's implanted toward the inside of the cortex.
This also has an outward bulge, so this
is quite a large focal metastasis.

Comparison to Foreign Body Implantation

It's interesting that metastases do implant
in a different part of the sinusoids in the lymph node than do foreign bodies.
Silicon or
or carbon tend to implant in the medullary sinusoids
and fill the lymph node from the inside out.
Well, on the other hand, metastasis tend
to create cortical thickening
and affect the hilum.
From the outside in now

Criteria for Distinguishing Normal from Abnormal Lymph Nodes

we have a whole series of findings
that can help distinguish normal from abnormal lymph nodes.
This is a small micro metastasis that's implanted in a
subcapsular sinusoid
and this is an afferent lymphatic completely
filled with metastasis.
But one of the criteria
that is most frequently used is size.
It's not a very good criteria and
because I showed you early on that atrophic lymph nodes
that are three or four centimeters in diameter may have a
very thin cortex on earth.
The slightest bit worrisome while a seven millimeter lymph
node may be completely replaced by a metastasis
but would have a thick cortex.
So size turns out not to be very good.
If you're gonna use size,
you should never use the maximum diameter.
You should only use the minimum diameter.
And the number most often used is greater than one
centimeter in minimum diameter.
But I would suggest not using size at all
and relying more on morphology.
Another published finding about abnormal lymph nodes is
abnormal rounding of the lymph nodes.
And this is indeed a true finding,
but it tends to be a late finding.
Eccentric cortical thickening
or symmetrical cortical thickening tend to occur
before rounding occurs.
Abnormal hypo echogenicity the cortex is another reported
finding from metastasis.
And again, this is a true finding,
but we virtually always use harmonics when we're looking at
axillary lymph nodes
and with digitally encoded harmonics.
The lymph node cortex always appears more hypo hypoechoic.
That's why we use it to find lymph nodes.
It makes them easier
to distinguish from the surrounding fat,
and I can find more lymph nodes faster
with harmonics than I can without.
But by using harmonics, we remove the value
of hypo echogenicity
'cause all lymph nodes appear hypoechoic with harmonics.
The best finding is morphology.
And again, cortical thickening is the hallmark
and eccentrical, cortical thickening
is the best finding of all.
It's the most specific for metastasis,
and you would specifically wanna target your biopsy
to the portion of the cortex that is abnormally thickened.
This can present as an outward bulge.
As I illustrated earlier,
if the implantation site is more toward the subcapsular
sinusoid or it can manifest itself
as an abnormal hilar indentation.
If the implantation site is more toward the inside
of the cortical sinusoid toward the medulla, we can see
complete compression or displacement of the hylum
or complete obliteration of the hylum by
a more severe replacement of the cortex by metastasis.

Tiebreakers for Reactive vs. Metastatic Nodes

I mentioned that when we get symmetrical cortical
thickening, it's very difficult to distinguish
a reactive node from a metastatic node that's
more extensively replaced by metastasis
and that we need a tiebreaker to make this distinction.
There are several possible tie breakers.
You can compare the relationship
between adjacent lymph nodes.
You can compare right to left symmetry
because most reactive lymph nodes are reactive to some
systemic inciting factor
that would make the adenopathy symmetrical.
You can look at the capsule for loss
of margin and irregularity.
You can look at color doppler flow patterns,
and you can put look at pulse doppler,
spectral waveform patterns.
All of these things can be helpful in distinguishing a
reactive from a metastatic node,
but the truth of the matter is, in most cases,
in the vast majority of cases, all you need
to do is rotate your probes slightly within the axilla.
Try to bring two adjacent lymph nodes into the same field
of view side by side.
And if one has an abnormally thickened cortex
and the other does not, it strongly
favors metastatic disease.
Etiologies for lymphadenopathy
that cause reactive nodes tend to cause all
of the lymph nodes in the EXL that have cortical thickening.
So symmetrical involvement of two adjacent nodes would tend
to favor reactive nodes.
Asymmetric involvement between two nodes would tend
to favor metastasis.
And again, of all these criteria,
I believe size is the least useful
and we generally just don't look at that at all.

Use of Harmonics in Imaging

This is just an illustration
of fundamental imaging on the left
and digitally encoded harmonics on the right.
And notice that the cortex
of the lymph node is more hypo coic relative
to the surrounding fat with harmonics than it is without.
It makes it easier to find the lymph node.
It makes it easier to evaluate the cortex of the lymph node,
and that's why my preference is
to always use harmonics when I look for lymph node as long
as I can obtain adequate penetration with harmonics.
The problem is this is a markedly hypo coic cortex
and it removes the value
of market hypo echogenicity as a finding.

Handling Morphologically Abnormal Lymph Nodes

Now this is a an illustration of various types
of morphologically abnormal lymph nodes
and how we would deal with them
in the center is a normal appearing lymph node
with verdes symmetrical hypo echoic cortex
and a
a normal appearing echogenic mediastinum or hylum.
In the first example here we have
symmetrical cortical thickening.
Notice that I've put a white outline around this image
and the white outline I illustrates to me
that this is a non-specific lymph node.
This could be a reactive node
or it could be a node containing a lot of metastasis
that's so extensive.
It's caused symmetrical cortical thickening.
I need to go to my first tiebreaker
and that first tiebreaker is gonna be
what does the adjacent lymph node look like?
The next two lymph nodes show
asymmetric cortical thickening.
I've put a little red outline
or a pink outline around this indicating
that this is high risk.
This is the hallmark for metastatic disease.
This is metastas still proven.
Otherwise I don't need another tiebreaker.
I don't need color doppler, I don't need pulse doppler,
I don't need to look at the opposite ex.
I need to biopsy these lymph nodes
and I specifically need to target my biopsy to the portions
of the cortex that are abnormally thickened.
The next case illustrates rat bite indentations
of the mediastinum.
This again has a pink line around the outside
because it strongly favors metastasis over
a reactive lymph node in association with the rat bite.
Indentations is eccentric cortical thickening.
So again, this is metastasis until proven.
Otherwise, I wanna biopsy this lymph node
and I wanna specifically target my biopsy
to this portion of the cortex.
I don't wanna biopsy the thin part of the cortex
because I might get a false negative.
These are two examples of flattening
and compression of the mediastinum,
which is also another way of saying
that we have symmetrical cortical thickening
of a more severe degree.
Even though the symmetrical cortical thickening is
of a more severe degree, this is non-specific,
these lymph nodes may well be reactive
rather than metastatic.
This is where I want to go
to my tie breaker again and again.
The key tie breaker I want to use first is to compare
to adjacent lymph nodes.
This is an example of displacement of the hilum to the side of the lymph node.
This really is the same as eccentrical, cortical thickening.
I've put pink around the box indicating
that this is a high risk lymph node for metastasis
and once again, I don't need a tie breaker.
I don't need color doppler or pulse doppler.
I just need to biopsy this lymph node.
And I need to specifically target the
thickened part of the lymph node.
This is a lymph node that has complete obliteration
of the hilum on a theoretical basis.
This could be necrotizing lymph adenitis,
which is benign,
but in those cases there would almost always be clinical
findings of infection
or inflammation that are quite obvious.
And in the patients that we would be scanning,
they would mostly be asymptomatic.
So this really is an indication of metastasis to prove
until proven otherwise, unless there are obvious signs
of inflammation or infection.
The final situation is loss of the lymph node capsule,
irregular or angular or micro lobulated margins.
And this tends to indicate a lymph node
with per nodal invasion.
This is metastasis will proven otherwise.
In all of these other instances, you could use FNA
to prove that the thickened part
of the cortex had metastasis,
but in this case, you would specifically wanna use core
biopsy and you would wanna have part
of your core involve a lymph node
and part of your core involve the peri nodal tissues
to confirm not only that this is a metastatic node,
but there is associated per nodal invasion.

Microcalcifications as Definitive Sign

There is one last instance in which we would know
that is this is metastatic disease for certain,
and that is a case where the primary lesion in the breast
has micro cals
and the lymph node also has microcalcifications.
In that case, it's always gonna be metastatic breast cancer
until proven otherwise.
I've seen maybe one
or two cases of metastatic ovarian cancer
to axillary lymph nodes that that had a similar appearance.
And of course, thyroid lymph nodes in the neck can have this
appearance, but in the axilla it's gonna be metastatic
breast cancer to proven otherwise.
So we need to biopsy that lymph node.

Using Adjacent Lymph Nodes as Tiebreakers

This just shows how we use the appearance
of adjacent lymph nodes as a tie breaker
to help us distinguish reactive from metastatic lymph nodes.
Here's a lymph node that has
symmetrical cortical thickening.
This is non-specific.
This could be due to a reactive node
or it could be due to a metastatic node.
But the adjacent lymph node has a normal appearance.
So the asymmetric involvement
of two adjacent lymph nodes strongly favors this being
a metastatic node.
This is a more severe example.
The hilum is completely obliterated in this lymph node.
On a theoretical basis, this could be
necrotizing lymphadenitis,
but the adjacent lymph node is perfectly normal
and there's no evidence of inflammation.
So this has to be metastasis tori.
Otherwise, and this is another case
where we have complete obliteration of the hili
and abnormal enlargement, abnormal hypo echogenicity,
but the adjacent node is perfectly normal.
This would never occur in reactive lymph nodes.
This is a virtually always gonna be metastatic disease.
So the simplest tiebreaker to use in cases
that are non-specific between reactive
and metastatic nodes is simply to compare
with adjacent lymph nodes.
You can compare to the contralateral side if you're unable
to rotate your probe
and find two lymph nodes in the same field of view.
Here we see a morphologically abnormal lymph node
that's enlarged, has cortical thickening
and obliteration of the hilum
and the contralateral lymph nodes are normal.
Unless you have obvious signs
of inflammation in the breast
or arm, this is gonna be metastatic disease
and not reactive lymph nodes
because reactive lymph nodes are generally gonna be some
systemic etiology that causes them to be bilateral.

Histology and Doppler Findings

Now the histology of lymph node metastases is identical to
that of the primary in at least 85% of cases.
And theoretically I would think even more than that.
What that means is if the primary lesion is hypervascular,
you should expect the metastasis to be hypervascular.
So this is the primary lesion
with hypervascular uncolored doppler
and this is a metastatic lymph node
that shows similar hyper vascularity.
If the primary lesion
has high resistance,
high peak systolic flows within the nodule,
not in the surrounding tissues,
but within the nodule, then you would expect similar flow
within the metastasis.
In fact, there is quite a difference in the waveform
morphology between the pulse ler,
spectral waveforms and metastatic nodes and
and those of reactive nodes.
This is a classical high resistance, high peak systolic pattern that we see with a lymph node metastasis.
And this is a classical reactive lymph node appearance
with a low rounded systolic peak
and much lower impedance blood flow.

Vascular Patterns on Doppler

Finally, you can actually look at the pattern
of blood vessels on color or power doppler.
This is a small seven millimeter lymph node
that's just completely replaced
with metastasis showing again that size
is a very poor criterion for whether
or node is metastatic or not.
This is the hilar vessel feeding this lymph node
benign lymph nodes, reactive lymph nodes,
and in some cases low grade lymphomas tend to only be fed
by hilar vessels that arbor rise to various degrees within
the lymph node hilum supplying the entire lymph
node from the hilum.
On the other hand, metastatic lesions often develop trans
capsular feeding vessels because of the metastases implant
and the cortical or subcapsular sinusoids.
And if they generate neovascular,
that neo vascularity comes in through the periphery of the lymph node.
So if you see a lymph node
that contains trans capsular feeding vessels
that strongly favors it being a metastatic lesion
or occasionally a high grade lymphoma,
if it just has hilar vessels that arbor rise
to various degrees as we see in this case associated
with symmetrical cortical thickening, that def tends
to favor a benign reactive node
or in a few cases, maybe a low grade uh, lymphoma.
This is a classical reactive lymph node symmetrical cortical
thickening and a single arbor rising hilar feeding vessel.
And this is a classical metastasis.
It's markedly hypo coic eccentrical cortical thickening
with the hilum displaced out of the lymph node.
It's abnormally rounded.
It has not only a hilar feeding vessel,
but it has trans capsular feeding vessels.

Clinical Workflow and Biopsy Examples

This is just an example of how we work up our patients.
This is a birads five lesion that turned out
to be intermediate grade invasive ductal cancer.
We performed core biopsy on this lymph node.
We looked at the axillary lymph nodes
and there was a non-specific node
that had symmetrical cortical thickening,
but the lymph node immediately adjacent to it was normal.
So our first tiebreaker said that this was more likely
to be metastatic disease than reactive node
and we perform a core biopsy on the lymph node proving
that it's a metastatic lymph node.
You could perform an FNA on this lymph node as well
because we do not have evidence
that there's per nodal invasion.
Once we've decided that the lymph nodes are abnormal,
at least at level one lymph nodes are abnormal
and we've decided that we're going to biopsy the lymph node,
we always wanna examine the lymph nodes at least one level higher
than the definitively abnormal lymph node.

Axillary Lymph Node Levels

The lymph node levels in the axilla are decided
by the pectoralis muscle,
which we can see transected right here.
It would normally lie under this trapezoidal area.
Lymph nodes that lie posterior
to the pectoralis minor muscle are level two nodes.
Lymph nodes that lie inferior
and lateral to the lateral edge
of the pectoralis minor are level one nodes
and lymph nodes that lie superior
and medial to the medial border.
Of the pectoralis minor muscles are level three
or infraclavicular nodes.
We always want to go one level higher than the
nodes are positive.
So if we see definitely abnormal level one nodes,
we wanna look at level two and rotter nodes.
If we have level two nodes, we wanna go to level three.
If the level three nodes are abnormal,
we wanna look at the supra and jugular nodes
and in some cases,
we will wanna look at the internal
mammary lymph nodes as well.

Imaging Views of Levels

This is just an illustration
of an anti radial view in the axillary segment
of the breast showing the pectoralis major muscle in front
and the pectoralis minor muscle in back things
posterior to the pectoralis.
Minor muscle will be level two nodes
and things lying inferior
and lateral to the lateral edge
of the pectoralis minor muscle will be level one nodes.
And notice that between the pectoralis minor
and major muscles is a small lymph node, that's a
a rotter lymph node.
In the strictest sense, these are not level two nodes,
they're rotter nodes, which are different,
but they do lie as the same at the same
level as rotter nodes.
They can contain metastases
and they can be a cause for local recurrence
within the chest wall.

Examples of Multi-Level Involvement

Now here's an example of a patient in whom we
did what I suggested.
We saw abnormal level one nodes.
We obtained an extended field of view
to show the pectoralis major muscle in front
the pectoralis minor muscle behind.
Remember that the lateral edge
of the pectoralis minor muscle shown by the right edge
of this rectangle determines level
one versus level two.
So the level one node is inferior and lateral.
The two nodes behind the pectoralis minor muscle are level
two nodes, but the medial edge
of the pectoralis muscle is shown by the left edge
of the rectangle and there is a lymph node
that lies superior to it.
And here's the clavicle.
So this is a level three lymph node.
So in this case we have adenopathy involving levels one,
two, and three.
And because this is positive, we do wanna go
above the clavicle and look at the uh, jugular
and supraclavicular nodes
and maybe even the posterior cervical nodes.

Rotter Nodes

This is an example of a metastasis bearing rodder node.
Here's the pectoralis minor muscle behind the lesion
pectoralis muscle in major in front of it.
And this is a metastasis bearing rodder lymph node.
There is a large vessel that is runs between the
pectoralis uh muscles and this is a normal vessel.

Extended Evaluation to Supraclavicular and Cervical Nodes

Now the first case I showed you had level one,
level two and level three nodes.
So in that case we wanna go, we want
to go at least one level higher.
So we did. These are supraclavicular lymph nodes,
they're morphologically abnormal,
these are jugular lymph nodes.
They're morphologically abnormal all the way up to uh, level
three in the neck.
There are levels of cervical lymph nodes as well.
And these are posterior cervical lymph nodes.
These are the farthest from the ex
abnormal lymph nodes we saw.
So in this particular case we did a core biopsy on
level one nodes in the axilla
and I did an FNA on the highest jugular lymph node to prove
that these were all metastatic breast cancer.

Internal Mammary Lymph Nodes

We can see normal internal mammary lymph nodes.
Some of the literature has suggested that
that is not the case, that we cannot see them.
Normally they're five to seven millimeters in long axis.
We usually see them in the second and third inner spaces
and they're most commonly seen just
above the costal cartilage, which lies right here.
But they can be seen anywhere along the intercostal space.
Spatial compounding can help
because it brings out the capsule of the lymph node.
Notice that we tend not to see the hyper coic
or echogenic hilum that we see in axillary lymph nodes.
This is because that's often the case
in smaller lymph nodes.
And I think because the resolution that we scan
with is reduced because of reflection
and refraction of the beam by the intercostal tendons.
In older women who have congestive failure
and increased right atrial
and diastolic pressure,
the internal mammary veins can become very dilated
and tortuous and it can be difficult to sort out
what may might be just a torturous internal mammary vein
from lymph nodes.
So color or power doppler can be very
helpful in that respect.
This by the way, is simply a reflection artifact off the
interface of the lung that's not real.
It's a reflection of this internal mammary
vein, lung anteriorly.
Sometimes you can use fremitus
to help you find internal memory lymph nodes
because they vibrate differently from the
intercostal tendons.
Notice how the artifact is transmitted beautifully
through the intercostal tendons and muscles
because they're oriented in a plane that's
perpendicular to the lung
and they allow the vibrations
to climb outta the lung really well.
But the lymph node doesn't transmit the fremitus well.
So you can outline the internal memory nodes,
but using FDIs in some cases,

Incidence and Appearance of Abnormal Internal Mammary Nodes

Some of the literature talks about a 10
or 15% risk of internal memory metastases.
We find it to be less than that.
We find the cases where it's most likely to occur
to be large deep medial lesions
because the deep medial part
of the breast may preferentially drain
to the internal mammary lymph nodes.
But most medial lesions drain to the peria
or sappies plexus and then to the ex.
So when we most often see
abnormal internal mammary lymph nodes is when they're
so-called tumor damming in the axillary lymph nodes.
This is a fairly large two
and a half centimeter high grade invasive ductal cancer.
There's gross metastatic disease within the axilla, lots
of completely replaced nodes.
These nodes are so replaced
that the lymphatic channels draining to them are obstructed.
So the patient has developed collateral pathways that drain
through the internal mammary nodes
and that's when we find gross internal
mammary lymphadenopathy.

Biopsy of Internal Mammary Nodes

Now we have tended not
to perform FNA on these internal mammary lymph nodes to
confirm that they are positive,
but it is certainly possible to do this.
One thing to keep in mind is
that many so-called recurrent carcinomas within the chest
wall post mastectomy arise from
unrecognized lymph node metastases.
And I think if we do a better job
of recognizing these prospectively,
we can either help direct the surgeon to remove these
or direct booster doses of radiation
to attack these.
But here's a chest wall recurrence that really
probably came from an internal memory lymph node.
And here are chest wall recurrences
that I'm sure arose from rotr lymph nodes.
Here's the pectoralis major muscle.
Here's the pectoralis minor muscle
and this so-called chest wall recurrences,
in fact metastatic disease in rotter lymph nodes.
Here's another case of a very severe chest wall recurrence.
This is the sternum.
This lesion is arising just lateral the sternum, right
where the internal mammary lymph nodes lie
and it's grown forward
and it's actually covering the anterior aspect of the sternum.

Summary

So in summary, we always
evaluate the axillary lymph nodes in patients
that have suspicious
or malignant breast nodules in whom we are going
to perform an AONE guided biopsy of some sort.
If we find an abnormal lymph node, we biopsy it.
But remember, a positive
staging alt sound is always more valuable than a negative.
We can't see microscopic disease,
we can only see gross disease.
A grossly abnormal alt sound leads to biopsy of lymph nodes
and confirmation of metastatic disease.
A positive alt sound
and a positive biopsy can obviate a sentinel
and node procedure and that's our goal here, is
to let the surgeon go straight to full axillary dissection
and not have to perform the sentinel node procedure.
It cannot obviate the axillary dissection.
The patient is still gonna need an
axillary dissection in those cases.
But remember that a negative staging ultrasound
or a negative biopsy of an abnormal appearing a reactive
lymph node hasn't really accomplished much.
The patient will have
to have a sentinel node procedure if that wa is
what the surgeon was originally planning.
And it will just represent an extra procedure.

Future Developments

The last thing I wanna show you is
possible future development.
I'm not actually doing this,
but this is being done at Thomas Jefferson University by Dr.
Goldberg and others.
And it's a lymphatic also in contrast agent
that can be direct directly injected into the
subcutaneous fat.
As of yet. This is being done in animals,
rabbits
and pigs, but not in humans.
But you can inject directly into the subcutaneous fat.
The hyper coic contrast the sends the lymphatic vessels,
fills the cortex of the lymph node making it hyper coic.
It's been shown to correlate well with
radionuclide methylene blue dye injections.
And this is it, it happens in a matter of
seconds to minutes.
Here we can see a pig lymph node filling from the
inside out over a matter of
about 40 seconds.
Here the cortex is completely filled with contrast.
Now notice that this is filling in the opposite direction
that I told you lymph flow occurs in humans and that's
because this is in a pig.
Now the human humans would indeed fill from the
subcapsular sinusoids inward,
but the important thing is that
where there is metastatic disease,
the contrast doesn't enter.
The lymphatic channels
of the lymphatic sinusoids are blocked.
So this is a lymph node almost completely replaced
with metastatic disease.
There's only a small area of cortex that's still normal.
That is the area that fills with contrast.
This is all area filled with metastasis.
Now the contrast isn't particularly helpful in this case
because this is so obvious.
Obviously abnormal, we'd easily be able to detect this
with Olson without contrast
and easily guide our needle
to the correct part of the lymph node.
But that is not the case in this particular situation here.
Most of the lymph node is normal.
There's only a small metastasis bearing area
of the lymph node, but we can pick that area out
because of the lack of contrast enhancement.
This might be a morphologically normal lymph node on
grayscale ultrasound alone.
So not only would the ultrasound contrast agent help us
determine that this is an abnormal lymph node likely
to contain metastasis,
but would precisely guide our needle to the correct part
of the lymph node to document that it is positive.

Conclusion

So thank you for listening.
I think it's important when we evaluate breast lesions
that we try to help the surgeon
and the patient as much as possible
by at least doing some preliminary staging.
I will not say that alt sound is better than MR for staging,
but I do think alt sound is better than MR
for evaluating lymph nodes.
And I think we should be aggressive in mapping out the extended disease in cases where it helps.
I don't think we should be too aggressive about biopsying
lymph nodes that might be reactive
because we just perform an extra procedure
and don't accomplish anything.
I think it's important that we go through the rigorous
exercise of trying to determine whether metastasis
or a benign reactive lymph node is the more likely etiology
for the abnormal morphology
before we commit ourselves to core biopsying
or performing FNA on that lymph node.
Thank you.