In the previous discussion, we looked at neutrophilic
leucocytosis in great detail.
Let’s go ahead now and take a look at what
Elevated WBC count, yes, that’s where you
begin and now, you have an absolute lymphocyte
count greater than 4000 in adults or in a
child, even higher 8000.
What is your normal WBC count?
Good, 4500 to 11,000.
If you can remember some of these individual
What kind of infection causes more lymphocytosis?
Viral or bacterial, especially viral, but
could also be bacterial.
I give you Bordetella Pertussis, chronic inflammation.
What does that mean to you?
At some point in time, the neutrophils did
not disappear or undergo apoptosis, they are
being replaced by macrophages and lymphocytes
Notice, as an example, I did not put corticosteroids.
Corticosteroids would cause lymphopenia.
You must memorize that, if you haven’t already.
The drug that I had given you example would
be anticonvulsive therapy and Phenytoin.
With lymphocytosis, increased production might
be a possibility or decreased entry into a
lymph node, welcome to Bordetella Pertussis,
which is a bacteria.
In either case, it finds lymphocytosis.
Antigenic stimulation of T-cells causes them
to take an atypical morphologic change, if
we are talking about EBV and remember, in
infectious mononucleosis referring to Epstein
Barr virus and I will show you a picture coming
up and the-and the picture will be a lymphocyte
which looks atypical.
Opt-Often times it is the nucleus, think about
the nucleus of a lymphocyte, what does it
A sphere, sometimes a pathology recall an
atypical lymphocyte that is found in EBV or
CMV as a ballerina skirt, you will see what
I am referring to.
Heterophile antibodies in acute phase is known
as a monospot test, very, very sensitive.
This is what you will be using in the United
States for-for your practice, especially in
If this comes back to be negative, you could
be pretty darn sure that your patient now
is mono free and if you want absolute confirmation
then you are called… what is something called
the Epstein Barr virus nucleic acid type of
issue, but this takes months, you don’t
have this kind of time.
You see that?
It takes months.
You, as a clinician, you want something fast
and effective, then you are going to use the
monospot test, but if you want confirmation,
EBNA, it might be a possible-possible test
Remember, you are worried about splenic rupture
in this patient.
In addition to EBV, viral hepatitis, cytomegalovirus,
toxoplasma may result in this particular type
of morphology that I will take a look at-that
you will take a look at and it is called an
atypical lymphocyte, I also call a Downey
You know it as being a Downey cell, don’t
Let’s go ahead and take a look at that atypical
Take a look at these cells here, these are
lymphocytes, they do not look normal whatsoever.
It is imperative that you don’t go back
and take a look at what normal is, I have
shown you one.
The nucleus of a lymphocyte, which you are
seeing here dark purple, normally should be
perfectly spherical, just about and then nucleus
of a lymphocyte should be the size of the
First off, this doesn’t even look like a
sphere and second off, you can’t even compare
it to the size of the RBC.
You find lots of cytoplasm and the one in
the middle maybe, if it is typical text book,
it is called what is known as a ballerina
If you see it, so be it; if you don’t, whatever,
let it go.
It is just a description, they are not going
to put it in a stem, but as pathologists,
The point is these are atypical lymphocytes.
When would you find this?
EBV being a big one.
Do not forget about CMV, toxo and maybe perhaps
Here, we will continue taking a look at leucocytosis.
Here, the increase in WBC count was caused
Welcome to eosinophilia.
Allergies, asthma and also helminth infection
will cause eosinophilia causing a rise in
your WBC count.
From the granule of the eosinophil, especially
parasitic infection, you are going to be releasing
major basic protein so that you can try to
kill off the parasite.
Basophilia, whenever you think about basophilia,
for the most part remember, this is at the
basement of the hierarchy of your WBC, at
a measly 0.3 percent.
If you find your WBC count to be elevated
and it is due to a basophil, make sure you
know what a picture looks like.
What does a granule look like by the way in
Oh, excuse me, apart from what it looks like,
what does it contain?
It is a very, very dark and it contains histamine.
One of the major myeloproliferative disorders
that may contribute to basophilia is chronic
Monocytosis, chronic inflammation EBV, TB,
Salmonella, many, many, many organisms.
Our topic here is leucopenia.
Let’s begin by looking at corticosteroids.
Corticosteroids may bring about lymphopenia
due to apoptosis of B and T cells.
Eosinopenia may also occur, once again, apoptosis.