We now move on to another
and you want to move
away from astrocytoma.
We have now completed our discussion
of astrocytoma officially.
And now we move on to these
myelin production cells.
But now, these myelin
production cells of the CNS
has now become a neoplasia,
a primary brain tumor.
Welcome to oligodendroglioma, okay?
So keep your astrocytes separate
from your oligodendrocytes.
This is the most common in
fourth and fifth decades.
Patients often have several
years of neurologic complaints
including seizures prior to diagnosis
and found predominantly in the cerebral
hemisphere specially in the white matter.
Now, these are an introduction
to your oligodendrogliomas.
What else might you
be looking for?
gray masses often with cysts.
Remember, these are not
referring to astrocytes.
And oftentimes, you’ll
The sheets of the regular
cells, this is important.
Please pay attention to spherical nuclei
containing finely granular chromatin
surrounded by a clear halo.
Picture that for me.
So you have the nuclei, which
is perfectly circular.
I want you pick
up an egg for me.
I have about a dozen
eggs a day on average.
And every time I crack an egg,
I always think of oligodendroglioma
as you should as well.
When you crack an egg and you
placed it properly in the pan,
the yolk is perfectly
And then around that nucleus, that's
spherical, you have that white halo.
That’s what you’re thinking about
here with oligodendroglioma,
very specific for
It usually contains a delicate
network of anastomosing capillaries,
that is another huge point.
Pay attention to lots of angiogenesis
and resulting in capillary formation.
Obviously, with any type of neoplasia,
you’re going to find increased angiogenesis,
but the combination of a fried egg
and the evidence of angiogenesis,
no doubt, this is
I like saying this word.
It’s actually really fun.
I don’t know what it is, but it
brings me satisfaction to the brain.
Anyhow, clinical features,
average survival, five to ten years and
more chemoresponsive than astrocytomas.
Do you understand
Astrocytomas, quickly run through
the ones that we’ve talked about
or the ones you should know.
What you want to do is keep
your adult astrocytoma
separate from your child
So therefore, keep your pilocytic
separate from the rest
including your fibrillary,
anaplastic, and glioblastoma.
Here, chemotherapy, well, could benefit
a patient with oligodendroglioma.
If you take a look at this
picture, what do we find?
Fried eggs and bacon or sausage.
No, I’m joking.
So what do you find?
You find your spherical nuclei and what
do I mean by that bacon or sausage?
Obviously, referring to your blood vessels.
You see those “rods”?
Those are not rods, those are?
Formation of new blood
vessels and capillaries.
You see this picture,
no doubt you should reflexibly be able to
identify this as being oligodendroglioma.
What if you find a palisading
pattern that I showed you earlier
as far as histology and
it’s a primary CNS tumor?
Then you should be thinking
about glioblastoma multiforme.
I’m giving you specific histologic pictures
that are extremely high yield for you.
I’m not going to give you every single
histologic picture, that’s ridiculous.
So let’s stick with the
ones that are high yield.
Could I give it to you?
But for the sake of
time and efficiency,
and for the sake of
digestibility of the material,
let’s somewhat keep
this organized, please.
Neuroepithelial tumor that we’ll
take a look at here is ependymoma.
Please think about
your ependymal cells.
Now, what becomes important here
is going to the age and location,
that’s all that
you need to know.
You’ll know exactly as to
what you’re referring to.
Now, a couple of things here that I
want to talk to you about with a child,
the primary CNS tumor.
If I take you back to astrocytoma,
what is the most common astrocytoma
to be found in a child
and where would it be located?
You’re going to tell me --
I’m sorry. What did you say?
Pilocytic type of astrocytoma.
Cerebellum causing then obstructive
type of hydrocephalus, right?
Here, we have another
but this time, this
is an ependymoma.
Where is this located in a child?
Do you have ependymal
cells in the cerebellum?
Well, if I had to compare the two,
I would definitely put my bet
on your fourth ventricle.
It may result here once
again in hydrocephalus.
What kind please?
Take your time.
Understand it, don’t just memorize it.
Spinal cord is the most common
location in which population?
Maybe by the cauda equina.
Once again, location and
population is important.
And you’ll know about
Let’s talk about a little bit
more pathology about ependymoma.
Solid or papillary mass extending from
the floor of the fourth ventricle.
What do I mean who?
What’s the population?
Composed of cells with
regular, round to oval nuclei
A dense fibrillary background.
Tumor cells may form gland-like
round or elongated structures.
We call these perivascular
Once again, perivascular
The tumor cells form a
gland-like structure around
or elongated structure,
And so therefore, it’s
not a true rosette.
It’s a perivascular pseudorosette.
Because by rosette, you mean
that you have the lumen,
which would be extension
of the cancer cells.
If you don’t know what a rosette is, well,
a rosette is exactly as the name implies.
Think of a rose with petals, huh?
When’s the last time you gave
your significant other a rose?
It might be time to do so.
And the inspiration was
actually an ependymoma.
Anyhow, in medicine, we’re
kind of sick, but whatever.
Well, some people say sick, some
people say romantic, whatever.
so think of a rose with petals.
So the petals are
the cancer cells.
And what’s the lumen?
Well, if the lumen is an extension of
the cancer cells, that is a rosette.
But if it’s a round perivascular,
you can’t call that a rosette.
It is a pseudorosette.
It is a pseudorosette.
That is an important description here.
If it’s a child, most likely, where
would you find an ependymoma?
Floor of the fourth ventricle.
Where is it if it was an adult?
Where would you find ependymoma?
More or less in the spinal cord,
maybe down by the cauda equina.
Clinical features: Hydrocephalus.
Is that confusing to you
or is that crystal clear?
If it’s a child, floor of the fourth
ventricle, what are you going to cause?
type of hydrocephalus.
Poor prognosis, unfortunately.
Poor prognosis, unfortunately.