Our topic here is WBC pathology.
The various lymphoid tissue
that we shall take a look at
in this section include
the lymph node.
Examples clinically of when and how
the lymph node will be affected.
It’s important that we walk
through the anatomy of it.
A few words about the
spleen and the thymus,
all of this dealing with
leukemias and lymphomas
in this section in which students
tend to confuse quite a bit.
But by the time we are done, you’ll be
well-organized with the WBC pathology.
At first, we’ll take a look
at the normal lymph node.
Think about the lymph node
that we have in our body.
Think about spread that might
take place within the lymph node
depending as to what
kind of cancer.
For example, I mentioned a few times
that if it was breast cancer,
a prognostic indicator there would
be the axillary lymph node.
Whereas if you had a male and
there was lymph node involvement
with either your testicular
cancer or your scrotal cancer.
If it’s testicular cancer, then the
spread will be to the paraaortic.
We’ll mention these types of
spreads when the time is right.
At this point, it is important for us
to identify the following structures.
I’d like for us to start in the middle.
And by the middle, I mean
the germinal center.
This germinal center
that you’re noticing --
indentify it please –
In the middle.
Responsible for B-cell
type of proliferation.
Beyond that, you start getting into the
cortex, so this will be outer side.
And we have paracortex.
The paracortex will be the area
in which the T-cells are housed.
You have the subcapsular sinus
and this sinus will become
important to us at some point
when we talk about a particular
WBC pathology known as your
Langerhans cell histiocytosis.
Remember once again that
this is a lymph node
and so therefore, just like you would
have organization of many organs,
the cortex will
always be the outer.
The medulla will always be the inner.
Therefore, in the middle
here, we have the medulla.
And through here, you might
find macrophages and company
that might be located as
eventually making way
through what’s known as the
afferent and efferent lymphatics.
Our topic at first is
What does this mean to you?
“Hey, doc, it hurts.”
In my neck.
And upon further examination,
you’d find erythema
in the back of the neck
with oral examination.
This to you is a good news.
Of course, you’re not
going to tell the patient
that you’re happy that
it’s a painful lymph node.
But at least, you know most likely
that it can be cured and treated
And most likely due to
My topic is benign lymphadenopathy here
and the lymph node will be called tender.
Acute nonspecific lymphadenitis.
Inflammation of lymph node characterized by
cortical and/or paracortical hyperplasia.
Usually caused by acute infections
and by acute infection, we’ll be having
strep or staph being the most common.
Maybe perhaps causing pharyngitis.
A cat-scratch disease
is rather interesting.
If you have an immunocompetent patient
and gets scratched by a
cat and maybe perhaps
passes off a bacteria
called Bartonella henselae.
I mentioned immunocompetent
whereas you have a patient
who is immunocompromised,
maybe perhaps HIV positive,
the story, doesn’t it?
And this patient who is HIV
the introduction of
Bartonella in such a patient
results in a skin manifestation
known as bacillary angiomatosis.
It changes a
Tularaemia will be let’s say your
patient that goes into the woods,
goes for hunting and then ends up
developing an acute infection.
And so therefore, we
talk about rabbits.
Most frequent presentation would
be tender enlarged lymph nodes,
what that means is the fact
that it actually hurts.
And if the lymph node hurts, this is
a good news for you as a clinician.
It means that you have
quite a bit of arsenal to
make sure that you take care
of that acute inflammation.
Whereas if it’s chronic
this is dangerous.
This is not so
much benign is it?
Usually, case is long-standing and
the lymph node here, “Hey, doc."
'I have a lump on my neck.”
Does it hurt?
This raises red flags.
Take a look at your
And maybe perhaps even