Okay. Now we’ll just move up a little bit from the
neck, to the lymph nodes back to submental area.
So the lymph nodes in the neck. Of course
I’m sure all of you know about the lymph
nodes. How are they classified in terms of
levels? For example, if you
are given a case scenario with a patient with
squamous cell carcinoma somewhere in the head and
neck region,larynx, pharynx, even the
soft tissue, and they are going for lymph
node dissection and it says level IV lymph
node dissection. What does level IV mean?
If we talk about branches, basically you got
your sentinel at level I.
So which is level I? Sentinel.
Is that the first one, I think?
No, for example, if you’re asked to do a
lymph node biopsy from this side, from here
in the jugular chain, which lymph node will
that be? What level is it? You have
the hyoid bone here, anything above that is
called level I. So from the base of your skull
above the hyoid bone is level I, and level
I is divided into level IA submental region,
level IB in the submandibular gland.
Level I, above the hyoid.
Then you take your hyoid bone which is C3
level and then your cricoid cartilage which
is C6 level. So that’s
another landmark. You have your jugular vein
here, right? Your jugular vein. So your level
II, III and IV are upper jugular, middle jugular
and lower jugular. So it pretty much corresponds
to between your hyoid and thyroid cartilage,
thyroid and cricoid, cricoid and the sternum.
Got that? You don’t have to be precise but
you need to know II, III and IV.
Posterior triangle is level V.
In the midline, you have the pretracheal or
the paratracheal lymph nodes, which is level
VI. And then if you go into the sternum, below
the suprasternal notch, that is level VII.
So, if you are, if somebody has got a head
and neck cancer and they’re doing level V
lymph node dissection, that means they are
removing all the lymph nodes from here submental,
submandibular, from the internal jugular chain
and from the posterior triangle. So normally
we do level V neck dissection. Level VI
is quite advanced cancer where you
have to remove all the five plus the paratracheal
lymph nodes, which is only for advanced disease.
But usually level V lymph node dissection.
You are also asked questions on neck
dissection. When you do a neck dissection,
when you remove these lymph nodes, because
they are closely adherent to other structures
you may have to sacrifice some structures.
What structures are normally sacrificed in
a neck dissection? Have you come across radical
neck dissection? Modified radical neck dissection?
What do those terminologies mean?
Modified is… I can’t remember.
You can’t remember. You think about
anatomically, because these lymph nodes are so stuck
to the neck, that means you are operating
on such a closely confined anatomical area,
you just can’t strip these lymph nodes out.
So if the lymph nodes are infiltrated by malignancy
they’re usually stuck to the spinal accessory
nerve, stuck to the jugular chain and stuck
to the sternocleidomastoid. So sometimes you
may have to sacrifice all three of these.
So a radical neck dissection involves removal
of all the lymph nodes, removal of the spinal
accessory nerve, internal jugular vein and
the sternocleidomastoid muscle, okay? A modified
radical dissection is when you preserve one
or more of these three structures. Clearly,
if you can preserve all three, that’s fantastic.
But if you can’t, you may have to sacrifice
it. Because if you sacrifice it it’s significant
damage, if you think about sacrificing the
jugular vein then obviously the other side
is going to compensate but it’s going to
be quite stressful for the other side, right?
Likewise if you sacrifice the spinal accessory
nerve, loss of shoulder abduction, shrugging
of the shoulder, and sternocleidomastoid is
Okay, that’s about lymph nodes.
Moving up into the face. To understand the