At this juncture, we’re moving
onto a different classification.
A different classification
of primary CNS tumors.
Up until now, we have completed officially
our discussion of neuroepithelial tumors.
Under meningeal tumor, we’ll
begin by looking at meningioma.
You want to keep your meninges separate
from the brain parenchyma, please.
pathologically for every reason possible.
So therefore, with that said, arises
from the meningoepithelial cells
or meningothelial cells
of the arachnoid.
Think about where you are now.
Now, the growth,
vast majority are benign.
Whenever you say the word benign,
it all depends on the
behavior of the benign tumor.
Now if someone says that basal
cell carcinoma is benign,
basal cell carcinoma, benign
skin cancer, extremely common.
Benign, but my goodness if
it’s locally aggressive,
could you imagine if this tumor
was on the nasal region?
And then all of a sudden,
it starts growing locally,
it will completely
disfigure the face.
My point is, just because
something is benign,
it doesn’t mean that you are
able to ignore it or neglect it.
Because this is a benign tumor,
and what’s going to happen?
You have this tumor that’s growing,
growing, growing in the meningeal region.
What’s adjacent to it?
The freakin’ brain, come on.
So therefore, be careful.
You want to memorize
Slow growing lesion and that’s
the part that’s dangerous, huh?
Because your patient has no
clue that this is occurring.
Asymptomatic, which is
really scary, really scary.
And by the time the patient
is going to present to you
with this slow
growing, benign tumor,
could you imagine as to how
big this tumor would be
by the time presentation
is taking place?
Slow growing lesion that presents either
with vague, non-localized type of symptom.
Or, well, it depends on the
growth and location, right?
With focal findings, referable to the
compression of the underlying brain.
You can imagine as to how
big this tumor would be
in which finally your patient
is going to present.
Common sites would be the following:
parasagittal aspect of the brain convexity,
the dura over the
wing of the sphenoid,
or even the foramen magnum.
But really, think about all the
meninges covering the entire brain,
and as you do so, go from
one part of the brain
or one part of the meningeal
region to the other
and you’ve given yourself
a nice little story
of where you would
find your meningioma.
Now, these meningiomas may
express progesterone receptors.
And rapid growth, therefore may
be taking place during pregnancy
has been in fact reported.
So that’s an important point there that
you want to keep in mind with meningioma
and really a very
I would call this a
clinical pearl, huh?
Pathology of meningiomas.
It’s a rounded mass,
We know that because
it’s benign already.
Anything that’s benign
will be well-circumscribed
and then eventually, during
presentation, will cause compression.
Easily separable from the brain parenchyma
because we’re dealing with a meningioma.
It is an encapsulated neoplasm.
And we have overlying what’s known
as hyperostosis of the skull
and what that’s basically referring to
is the fact that above the meninges,
the bone is going to react.
Underneath the meninges, you have
compression-like symptoms, is that clear?
Tumor spreads in the sheet-like
fashion along the dura.
And now the lesion range
from firm to fibrous,
but this is what you want
to pay attention to.
Finely gritty and that’s because
of extreme calcification.
We then refer to this in meningioma
and this calcification is
called psammoma body.
From now on, whenever you
hear the term psammoma body,
you automatically, pathologically,
equate this to calcification by reflex,
Obviously, psammoma bodies could
be found in a number of places.
Here, apart from meningioma, you could find
this with a common malignant ovarian tumor
and that is then referred to as being
your serous cystadenocarcinoma.
And there are many places that
you would find psammoma bodies.
be one of these.
What does it mean to you?
In this picture, a psammoma
body is being shown to you.
And within that psammoma body,
you’ll notice that increased
eosinophilic or hyperchromatic
type of structure.
And that solid inside that body –
that solid structure then
represents the calcium.
This is meningioma.
Please be able to
identify psammoma body
and in a patient who is then
presenting with new onset seizures
and has taken years
for this to occur,
meningioma should be pretty
high on your differential.