In this lecture, we?re going to review central nervous system tumors in children.
So, in children, CNS tumors are the second most common pediatric malignancy.
About 20% of all cases of childhood cancer are CNS masses
and younger children are more likely to have embrional tumors
such as medulloblastoma compared to older patients.
This is generally a sporadic problem.
It?s without real risk factors or causes.
It?s just extraordinary bad luck,
although certain genetic syndromes may predispose patients
to development of CNS tumors.
So, to diagnose it as a CNS tumor, we have to take a good history,
do a physical exam, and do some diagnostic imaging.
Let?s start with the history.
So, the historical findings of CNS tumors in general
depend on the location of the tumor in the brain.
Symptoms may result from an increased intracranial pressure.
I would say the exception being pituitary adenomas
which generally don?t do that.
However, most other tumors can cause an increase in ICP
which will present with the classic finding of morning headache
and morning emesis.
If you think about it, the child?s been lying down all night
and there?s increased pressure because they?ve been in a resplendent pose
and once they get up and move around, the pressure may reduce slightly.
These patients may also be lethargic or sleepy, or feel out of it.
We may see other signs indirectly such as poor school performance,
fatigue, behavioral changes, weight gain or weight loss,
increased clumsiness, or walking difficulty.
So all of these can be signs of a problem in the intracranial vault.
Also, patients with focal seizures or with prolonged postictal paralysis,
that may be a sign of increased ICP.
So, then we have to do a good physical exam
and in particular, the cranial nerves are very important to evaluate.
As cranial nerve palsies are fairly common with brainstem lesions.
You may also see papilledema, you may see ataxia,
you may see a facial droop or weakness
which is really a cranial nerve palsy,
you may see hearing loss, and you may see diplopia,
especially diplopia in patients with a pituitary lesion.
You can also find focal symptoms if it?s a little bit higher up
such as hemiparesis or a hemisensory loss.
You may notice hyperreflexia or visual defects or seizures,
especially focal seizures are concerning,
and any hypothalamic tumor can present with a diencephalic syndrome.
The diencephalic syndrome is euphoria, hyperphagia, and anorexia.
Okay. Let?s talk about pineal lesions and optic chiasm lesions very briefly.
These can cause defects in pupillary constriction
and patients may have an inability to look upward.
This is called the Parinaud syndrome.
Also, we will do some diagnostic testing to rule out CNS tumors.
So the MRI with gadolinium is the imaging of choice.
It does require sedation in younger children.
Generally, we will also get an MRI of the spine
because generally there may be metastasis to the spine
or this might not be a tumor,
it could be something like acute disseminated encephalomyelitis
for example which presents with diffuse disease.
You may early, if you?re worried, get a CAT scan.
You might want to do a CAT scan, for example,
before you do a lumbar puncture
if you are thinking this patient might have meningitis
because you don?t want to cause an increased ICP to be depressurized
after the foramen magnum and result in a herniation.
So, we usually will do a CSF
though once we?ve made the diagnosis of brain tumor
to try and get cytology or cells.
So, there are a multiple ways, you can sit patients for a lumbar puncture.
Generally, for older patients we prefer the sitting position.
For younger patients or babies, you might do a lying down position.
Doesn?t really matter except remember, if you?re looking for an increased ICP,
you're gonna wanna use your manometer in the lying down position.
We will send this CSF for beta-hCG and AFP
which may be positive in teratomas which can present in the brain.