00:00
In this lecture
we're going to talk about
meningiomas.
00:03
The most common
primary brain tumor
that we see a really neat tumor
and something that I want you
to understand.
00:11
Let's start with a case.
00:13
40-year-old woman
who presents with headache.
00:15
40-year-old woman presents with
six months of progressive headache.
00:19
Now, new right-sided
hemibody numbness
and some mild weakness
with gait stumbling
over the past one month.
00:26
So this has been going on
for a little while.
00:28
She was seen in a
local emergency department
where a CT of the head
showed a left-convexity lesion.
00:35
And MRI the brain
was requested and performed
also showing a homogeneously
enhancing left-convexity lesion.
00:43
Examination shows
right-sided drift and pronation
which is where the arm pronate,
it turns and drifts down,
indicating subtle right-sided
and right arm weakness.
00:53
So what's the diagnosis?
Well, how do we think
about this case?
There's a few key features
that I want you to pick up on.
01:00
First, the onset
of this process is slow.
01:03
This took six months to develop.
01:05
So whatever is occurring
in the brain
is developing slowly,
and maybe a benign tumor.
01:11
The second is the
right hemibody symptoms,
which point to a left hemibrain
or left-brain problem
and that's where
we're going to go looking.
01:20
And then last is imaging
showed an extra-axial lesion,
or something that is concerning
for an extra-axial lesion
in the left-convexity.
01:28
And we'll look more at that.
01:30
And here we see
this patient's imaging.
01:33
So when we're looking at MRIs,
this is a T1 post-contrast
gadolinium enhanced contrast
enhanced imaging.
01:40
The left side of the patient
is actually on the right side
things are opposite.
So this is a left-convexity lesion.
01:46
And we see it's
homogeneously enhancing.
01:48
It's white all the way through it.
01:50
Actually, it with some of that
contrast extending out
on either side of this lesion.
01:56
So what's the diagnosis?
Is this a brain metastasis,
meningioma, pituitary adenoma,
glioma,
or vestibular schwannoma?
What doesn't look like
a brain metastasis,
we can see dural metastasis, but
this patient has no known cancer,
and this has been going on
for a while without concern
for growth pattern that would
suggest a brain metastasis.
02:19
It's not in the right location
for a pituitary adenoma,
which occurs in the sella turcica,
that midline structure
in the middle of the brain.
02:27
This is not typical
for what we see with gliomas.
02:31
Glial tumors and glial cells,
glial tumors arise
from the brain parenchyma.
02:35
This looks on the outside
of the brain,
on the covering around the brain.
02:39
This is nowhere near
that vestibulocochlear nerve,
so we don't think that this is
a vestibular schwannoma,
which typically presents
with hearing loss.
02:47
So this is a classic presentation
for a meningioma.
02:51
Typically a benign
slow-growing tumor
that's located
in the cerebral convexity.