Let’s take a look at the pathology of fibrillary astrocytoma.
This is a, you know the slide, you'll know everything that you need to know about fibrillary astrocytoma
which you wanna pay attention to prior was the gross and microscopic features of fibrillary.
It’s a grade II in terms of grading or classification under WHO.
Mean age here look at this, a young patient, less than 35.
Initial management is often observation if symptoms are not serious and often times you'll find that with brain tumors.
Mean interval to progression approximately 4-5 years, and management after progression is usually surgical resection, radiation, or both.
And mean survival after radiation and treatment is 6-8 years and this would be found what's on in your blue book.
The pathology for anaplastic astrocytoma, this is referred to as being your grade III under WHO classification.
The mean age here would be 40s to a relatively young; initial management is surgery and radiation -
you get in there you remove the sucker, recurrence is almost certain, anaplastic is absolute chaos,
remember mitotic rate is incredibly high.
Progression to glioblastoma is frequent, unfortunately, and could occur within two years.
Here are the management. If it’s symptomatic which is going to occur quite quickly,
it’s called surgical debulking, steroids for mass effect and maybe perhaps chemotherapy would be required.
Two down under neuroepithelial tumor, and what are these? These are astrocytomas.
Glioblastoma multiforme, you pay attention to this one. This is WHO grade IV.
Mean age here would be 60, necrosis or microvascular proliferation to diagnosis.
Remember we've talked about androgenesis taking place, proliferation of endothelial cells.
Initial management maximum surgical resection, but even then there's no guarantee.
Management after progression, symptomatic once again if chemotherapy is required, however take a look at the survival.
Mean survival after initial treatment, 1-2 years.
So then it comes into risk versus benefits and whether or not, well, you know,
that ends up becoming a behavioral signs steps of issue in terms of communication with the family
and whether or not they wish to opt for surgery and so on and so forth. Look for those type of scenarios.
Here’s a histologic picture of glioblastoma multiforme,
but what I want you to pay attention to is right there in the middle there,
and you’ll find a surrounding border of a pilocytic pattern of glioblastoma multiforme.
So of all the astrocytomas thus far in an adult, well, we look at anaplastic fibrillary
and here’s a glioblastoma multiforme. You wanna know its histologic picture in great detail.
Under astrocytomas, we have one that’s left, you'll notice that we talked about Grade II, III, IV -
grade II was fibrillary, grade III was anaplastic, and grade IV was a glioblastoma multiforme.
It came under the category of astrocytomas and astrocytomas are neuroepithelial tumors,
which means that particular tumor is then arising from your brain, brain, brain -- the parynchema.
So we have one left, that’s grade I. We leave this separate because pilocytic astrocytoma,
the reason that I separate the pilo and cytic because I want you to pay attention to cytic
and by cytic I want you to think of it as being cystic.
So when I say cystic to you, what does that mean? It means that you have a fluid filled compartment, don’t you?
So where is this fluid filled compartment located in this child?
Do you realize that the reason that this is kept separate of all the astrocytomas
is because this is the one that’s most commonly found in children.
Now, be careful with this. this pilocytic astrocytoma is the most common astrocytoma to found in a child.
And the reason I'm being very technical here is because if there's a question at any point in time that’s when post to you,
what is the most common brain tumor overall, primary in a child?
Then it will be medulla blastoma which we haven’t discussed yet, is that clear?
Okay, now let’s move on.
Typically occurs in children located in -- where is this cystic type of lesion located?
This cytic or cystic type of lesion is located in the cerebellum.
So how would your patient then present, now think about the cerebellum, in a child, what is it going to do?
It’s growing, it’s growing, and growing. What does it look like?
It looks like a cystic like structure and whenever you think of a cystic it’s fluid filled,
then if you have an imaging you can only imagine that what you're going to find
in the middle of the cyst would be of what characteristic?
Would it be opaque or would it be lucent?
Fluid appears to being lucent in this case and so therefore as it grows, it’s going to then impinge upon, what?
In front of the cerebellum, there you go. So now you're talking about the fourth ventricle.
Ah, this is not good, if you start then increasing the obstruction of the fourth ventricle,
then you are creating obstructive noncommunicating type of hydrocephalus. Keep those things in mind.
Usually cystic, so from henceforth the clinical pearls here would be children, cytic, by cytic
you refer to cystic located where, in the cerebellum therefore what kind of presentation?
Usually that would be in coordination with walking in other words maybe ataxia.
A quick little words about some of the remaining astrocytomas.
Pleomorphic xanthoastrocytoma typically once again here seen in children, could be found in younger adults as well.
Usually located in the temporal lobe. Pleomorphic, P, as in temporal lobe. Children perhaps, young adults.
And we have something called SEGA. When I was growing up back in the day, SEGA was actually a video game,
nowadays I don’t even know if it exists, but anyhow, subependymal we have giant cell astrocytoma.
And here you're thinking about this being periventricular kind of tumor and with tuberous sclerosis.
And of course, tuberous sclerosis being a genetic issue, with the particular gene known as TSC.
At this juncture we have now completed our neuroepithelial tumor classification or subtype of astrocytomas.
We’ll begin by looking at common adult type of astrocytomas
and we have now looked at the most common child astrocytoma or astrocytoma to be found in a child,
bling pilocytic, look at pleomorphic and SEGA.