Here, we’ll take a look at
a neuroepithelial tumor.
This is called medulloblastoma.
Right off the bat,
let me tell you,
medulloblastoma will be the
most common brain primary tumor
or primary CNS tumor in a child.
Now, with that said, let’s take a
look at what it’s referring to.
Sometimes, you see the abbreviation when
you’re reading a journal or whatever,
NEJM, what have you.
And you might see the
In fact, you have or you will.
It stands for primitive
neuroectodermal tumor, pNET.
You see it?
Here, you want to think of this
as being embryonal neoplasm.
I just began this discussion by calling
this a primary CNS tumor in a child.
The median age, seven.
Next, 75% in patients
16 years and younger.
That’s what your focus
should be on, is that clear?
20% of brain tumors in children.
So in other words, we have a
young population overall, huh?
Yes, 16 years, 75%.
However, 20% of brain tumors
overall, primary in a child,
that’s pretty high in terms
of percentage, trust me.
Yet another one,
right in that area in the vicinity of the
fourth ventricle and the cerebellum.
Right in that vicinity.
So give me three right now in a child
that will be in that region, three.
Most common astrocytoma
in a child, pilocytic.
What about an ependymoma?
It could be located in the
floor of the fourth ventricle.
And here we have a medulloblastoma.
Where is it located?
The midline of the cerebellum.
All of these could cause what?
type of hydrocephalus.
So as you can see here,
there’s a decent, decent list of
differentials causing non-communicating.
Rapid growth, rapid growth.
May occlude flow of outflow of CSF
resulting in hydrocephalus as we mentioned.
Now, these small blue cells -- so if
you want from now on, medulloblastoma.
Small blue cells is the
may then go into the CSF.
Keep that in mind.
If you take a look at this imaging
study, you’ll notice where are we?
You see that structure where
we have the cerebellum.
And you find that increased opacity,
which then represents a tumor.
It looks like it’s in the midline
of this child’s image of the brain
and therefore, you can notice
that now as it moves anteriorly,
that it’s then going to cause
obstruction of the outflow of your CSF
from the fourth
ventricle most likely.
This is medulloblastoma.
A couple of things that I wish to bring
to your attention under medulloblastoma.
You want to know this in greater
detail because it is a common, common,
primary CNS tumor in a child.
gray and friable.
of anaplastic cells.
Take a look at these small
cells with little cytoplasm
and hyperchromatic nuclei that are
elongated or crescent shaped.
And by hyperchromatic nuclei, we
are referring to this as being –
Take a look at these sheets
of small blue cells.
Clinical presentation is important.
pressure as you can imagine.
Ataxia because we’re referring to
the cerebellum being affected.
Clinical features, we have highly
malignant tumor, highly malignant.
disseminate into the CSF,
a common complication because of
its increased aggressiveness.
We call this drop metastasis.
Mets stands for metastasis.
unfortunately, in a child.
And that just makes me sad and it’s
radiosensitive, but poor prognosis.
Please make sure that you know
medulloblastoma in greater detail.