00:01
Our topic here is WBC pathology.
00:04
The various lymphoid tissue
that we shall take a look at
in this section include
the lymph node.
00:09
Examples clinically of when and how
the lymph node will be affected.
00:14
It’s important that we walk
through the anatomy of it.
00:18
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.
00:28
But by the time we are done, you’ll be
well-organized with the WBC pathology.
00:36
At first, we’ll take a look
at the normal lymph node.
00:41
Think about the lymph node
that we have in our body.
00:44
Think about spread that might
take place within the lymph node
depending as to what
kind of cancer.
00:50
For example, I mentioned a few times
that if it was breast cancer,
a prognostic indicator there would
be the axillary lymph node.
00:57
Whereas if you had a male and
there was lymph node involvement
with either your testicular
cancer or your scrotal cancer.
01:06
If it’s testicular cancer, then the
spread will be to the paraaortic.
01:10
We’ll mention these types of
spreads when the time is right.
01:13
At this point, it is important for us
to identify the following structures.
01:18
I’d like for us to start in the middle.
01:20
And by the middle, I mean
the germinal center.
01:23
This germinal center
that you’re noticing --
indentify it please –
In the middle.
01:28
Responsible for B-cell
type of proliferation.
01:31
Quite active.
01:33
Beyond that, you start getting into the
cortex, so this will be outer side.
01:37
And we have paracortex.
01:39
The paracortex will be the area
in which the T-cells are housed.
01:44
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.
01:57
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.
02:06
The medulla will always be the inner.
02:09
Therefore, in the middle
here, we have the medulla.
02:11
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.
02:23
Our topic at first is
benign lymphadenopathy.
02:27
What does this mean to you?
“Hey, doc, it hurts.”
Where?
In my neck.
02:34
And upon further examination,
you’d find erythema
in the back of the neck
with oral examination.
02:41
This to you is a good news.
02:43
Of course, you’re not
going to tell the patient
that you’re happy that
it’s a painful lymph node.
02:47
But at least, you know most likely
that it can be cured and treated
And most likely due to
bacterial infection.
02:55
My topic is benign lymphadenopathy here
and the lymph node will be called tender.
03:00
Acute nonspecific lymphadenitis.
03:03
Inflammation of lymph node characterized by
cortical and/or paracortical hyperplasia.
03:08
Acute.
03:11
Usually caused by acute infections
and by acute infection, we’ll be having
strep or staph being the most common.
03:18
Maybe perhaps causing pharyngitis.
03:23
Cat-scratch disease.
03:25
A cat-scratch disease
is rather interesting.
03:27
If you have an immunocompetent patient
and gets scratched by a
cat and maybe perhaps
passes off a bacteria
called Bartonella henselae.
03:37
I mentioned immunocompetent
whereas you have a patient
who is immunocompromised,
maybe perhaps HIV positive,
completely changes
the story, doesn’t it?
And this patient who is HIV
positive, immunocompromised,
the introduction of
Bartonella in such a patient
results in a skin manifestation
known as bacillary angiomatosis.
03:56
It changes a
complexion completely.
04:01
Tularaemia.
04:03
Tularaemia will be let’s say your
patient that goes into the woods,
goes for hunting and then ends up
developing an acute infection.
04:11
And so therefore, we
talk about rabbits.
04:17
Most frequent presentation would
be tender enlarged lymph nodes,
what that means is the fact
that it actually hurts.
04:23
And if the lymph node hurts, this is
a good news for you as a clinician.
04:26
It means that you have
quite a bit of arsenal to
make sure that you take care
of that acute inflammation.
04:36
Whereas if it’s chronic
nonspecific lymphadenitis,
Usually, case is long-standing and
the lymph node here, “Hey, doc."
'I have a lump on my neck.”
Does it hurt?
"No."
Nontender lymphadenopathy.
04:50
Take a look at your
differentials.
04:52
Autoimmune diseases.
04:53
HIV.
04:55
Chronic infection.
04:57
Drugs.