Our topic here is
We’ll begin with where are
we in terms of organization.
This is primary CNS tumor.
Under primary CNS tumor, we’re
looking at neuroepithelial tumor.
The classification of neuroepithelial tumor
will be your astrocytic or astrocytomas.
Let’s take a look.
Definition: tumor derived from,
as you can imagine, astrocytes.
And you think of these
as being glial cells
and how often have you come across a
description, a reading, or a narration or,
let’s say, a CPC, a pathologic conference
in which you’re sitting around
and you hear the
term glioma, right?
Well, this is what
we’re referring to.
So the fact that you have an astrocytoma,
please be aware that anatomically,
these cells, glial cells,
and at some point,
these would then be referred
to as being gliomas.
We’ll take a look at low-grade, referred to
as being fibrillary type of astrocytoma.
Anaplastic is never
a good thing.
Glioblastoma multiforme, we’ll be spending
time with this one in greater detail.
And the reason for that is it
is one of the most common,
unfortunate brain tumors
that occurs in adults,
but really, it could be seen
across the spectrum.
Then we have an astrocytoma that
occurs almost exclusively in children
or very commonly in children and this then
referring to your pilocytic astrocytoma.
And you’ll be focusing upon the
-cytic and I’ll tell you why in a bit
and then you can have your what’s known
as your pleomorphic xanthoastrocytoma.
Let’s take a look at
And under here, 87% of adult primary
brain tumors will be an astrocytoma.
That’s how important
these gliomas are.
80% of adult primary
you want to put yourself into
the category of astrocytomas.
Let it be your fibrillary, anaplastic,
or glioblastoma multiforme.
Usually arises in the cerebral
hemisphere as you can imagine
because we’re not dealing
with our meninges.
Usually presents with as you
can imagine, once again,
the brain parenchyma, so therefore
perhaps focal neurologic deficit.
Maybe there’s headache and maybe
there’s new onset seizures.
This is an important point.
Pay attention to the
Understand why these would be seen because
we’re referring to the brain parenchyma.
Inactivation of p53.
As soon as you have p53
that has been knocked out,
there is really nothing that is
modulating or regulating your cell cycle.
And so therefore, the cell is allowed to
remain within the cell cycle forever,
and so therefore may then result
in increased proliferation.
Please note: Over-expression of platelet
derived growth factor A or alpha.
PDGF, memorize that please for
a.k.a. gliomas, and
here we have adult.
You’ll notice here that the
astrocytoma that’s missing
in adult primary brain
tumor is which one?
Let’s talk about the gross
examination of your brain tumors.
Fibrillary astrocytoma: Poorly
defined, gray, infiltrative tumor
that expands and distorts
the normal brain.
The one that you want to pay attention to
here as well is glioblastoma multiforme.
Areas of firm and white or soft and yellow
areas representing your areas of necrosis.
And what’s dangerous about
glioblastoma is even
when you are trying to
surgically correct it,
there’s every possibility that
these will then come back
And in addition,
these particular neoplastic cells will
then seed -- seed, in terms of spread --
and by seeding, we mean it is then
going to pop into adjacent structures,
maybe perhaps even your
mild to moderate increase in
number of glial cell nuclei.
That should make perfect sense.
This is an absolute malignancy.
And this is an
And so therefore, we expect the nuclear
to cytoplasmic ratio to be quite high.
Extreme activity in the nucleus.
And we have nuclear pleomorphism,
intervening what’s known as feltwork
and make sure that you memorize glial
fibrillary astrocytic processes.
Your positive astrocytic
So you’ve got a couple of
things here to memorize.
Earlier, I told you about pathogenesis and
it could be the suppression of your p53.
Or number 2, your PDGF alpha.
and then please make sure under
astrocytoma, you keep in mind GFAP.
With the anaplastic, what
does that mean to you?
Complete chaos that’s taking
place within the nuclei.
So increased cellularity and nuclear
pleomorphism beyond belief,
marked mitotic activity.
complete poor prognosis.
And then we have a
You have a greater
I would highly recommend that
you know in greater detail
the microscopic feature
Increased mitotic figure
with necrosis and vascular
and we have perhaps endothelial
representing your angiogenesis.