Approach to a suspected brain tumor (pediatrics): Clinical sciences

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Introduction0:00–0:32

Brain tumors are histologically diverse and can range from indolent benign tumors to aggressive infiltrating malignancies.
Although both benign and malignant brain masses are associated with significant neurologic morbidity. They often present with nonspecific vague or intermittent symptoms.
These symptoms are related to tumor location, disruption of neurologic function and the onset of increased intracranial pressure or ICP.
When a pediatric patient presents with a chief concern suggesting a brain tumor. Your first step is to perform an ABCDE assessment to determine if they're stable or unstable.

Unstable Patient0:32–1:40

If unstable, stabilize the airway breathing and circulation, consider intubating your patient. If they demonstrate shallow, ineffective or absent respirations, then obtain IV access and consider administering IV fluids finally continuously monitor vital signs and if needed administer supplemental oxygen.
Here's a high yield fact, an enlarging brain mass can obstruct cerebrospinal fluid drainage causing elevated ICP if not treated promptly.
Increased ICP can lead to brain herniation, which is associated with long term neurologic sequelae and death. Signs of increased ICP include bulging, fontanelles, unilateral pupillary dilation, sometimes called a blown pupil, focal neurologic deficits, abnormal posturing and the cushing triad, which consists of bradycardia, a widened pulse pressure and irregular respirations known as Shane Stokes breathing.

Stable Patient1:40–2:39

Now that we've discussed unstable patients. Let's return to the ABCDE assessment and look at stable ones.
Your next step here is to obtain a focused history and physical examination. Presenting symptoms often include headaches which usually start in the morning and are relieved by vomiting, nausea and vomiting, seizures, changes in school performance or loss of developmental milestones.
The physical exam might demonstrate altered mental status, cranial nerve palsies, visual impairment, abnormal motor or sensory findings, hyperreflexia or ataxia because cranial sutures remain open until the first year of life.
Patients presenting before two years of age might also present with a bulging fontanelle or macrocephaly, which can be noticed with elevated head circumference with these findings, consider a brain tumor and obtain an MRI of the brain to look for a mass, then assess your patient for localizing symptoms.

Glioblastoma multiforme2:39–4:12

If history is significant for seizures, consider a hemispheric mass such as glioblastoma multiforme or a primitive neuroectodermal tumor.
In addition to seizures, these patients usually have focal weakness and sensory changes, possibly with changes in cognitive function including behavior, personality language and speech.
Older Children might report headaches while infants might demonstrate early handedness, exam findings might include an altered level of consciousness, motor weakness or paralysis, asymmetric reflexes and vision or hearing loss.
The MRI will confirm a hemispheric mass possibly with infiltration into the surrounding tissues. Once you've identified a mass, obtain a biopsy or resection with histology to confirm the diagnosis.
If histology demonstrates dense cellularity, high mitotic index, microvascular proliferation and foci of tumor necrosis, diagnose glioblastoma multiforme which is an aggressive astrocytoma.
Here's a clinical pearl. The who classification system is used to grade central nervous system tumors from grade one to grade four, which helps to determine overall treatment and prognosis.
Grade one tumors are benign and can be treated with resection. But grade four tumors are aggressive infiltrating malignancies that often respond poorly to resection radiation or chemotherapy.

Primitive neuroectodermal tumor4:12–4:44

Ok. Now, back to biopsy results if histology shows undifferentiated or poorly differentiated small round blue neuroepithelial cells diagnose a primitive neuroectodermal tumor.
Here's another clinical pearl. Another type of neuroectodermal tumor to keep in mind is an atypical teratoid or rhabdo tumor.
These rare, rapidly growing malignant masses can appear anywhere in the central nervous system and usually occur in Children under age five.
Ok. Now that we've discussed hemispheric masses, let's go back to our assessment of localizing symptoms.

Midline/Posterior fossa4:44–5:07

If the primary symptoms include headache and vomiting, particularly in the early morning. Consider a midline or posterior fossa mass tumors in these areas are more likely to obstruct cerebrospinal fluid drainage and produce symptoms of increasing ICP to further localize the tumor.

Midline mass5:07–5:22

Assess your patient for ataxia. If there's no evidence of ataxia, consider a midline mass such as a suprasellar or pineal mass and then assess your patient's linear growth if linear growth is delayed.

Craniopharyngioma5:22–6:11

Consider a suprasellar mass history usually reveals visual changes and vision loss due to pressure on the optic nerve, possibly combined with endocrine issues such as delayed puberty, diabetes, insipidus and thyroid dysfunction.
Common physical exam findings include visual field changes, papilledema, short stature and poor weight gain. If the MRI confirms a heterogeneous solid and cystic suprasellar mass, obtain a biopsy or resection of the mass with histology.
If histology demonstrates a complex tumor with stratified cells, multiple cysts with thick motor oil like fluid cholesterol cysts and keratin pearls diagnose craniopharyngioma, a large but benign tumor.

Pineal mass6:11–7:44

On the other hand, if there's no delay in linear growth, consider a pineal mass such as a pineal parenchymal tumor, benign germinoma, yolk sac tumor, choriocarcinoma, immature teratoma or embryonal cell carcinoma, pineal masses often cause difficulty with eye muscle movement leading to double vision and occasionally endocrine dysfunction such as precocious puberty, diabetes, insipidus and thyroid dysfunction time for a clinical pearl due to their proximity to the hypothalamus and pituitary gland, suprasellar and pineal tumors often cause endocrine dysfunction.
For example, pressure or invasion from suprasellar tumors can suppress growth hormone and gonadotropins leading to delayed growth and puberty.
However, pineal tumors that secrete beta hcg are associated with precocious puberty, particularly in biological males. Now, back to our patient during the physical exam, look for Perna syndrome, which is the triad of upward gaze palsy nystagmus and poorly reactive pupils, you might also notice papilledema and tremors.
If the MRI demonstrates a heterogeneous mass in the pineal region your next step is to evaluate tumor markers in the serum or cerebrospinal fluid.
Specifically measure levels of alpha fetoprotein or a FP and beta human chorionic gonadotropin or beta HCG. Now, if the A FP and beta HCG levels are normal order a biopsy or resection of the mass with histology, evidence of large round cells possibly with pinealocyte and pinealocyte rosettes confirms a pineal parenchymal tumor.

Pineal parenchymal tumor7:44–8:00

On the other hand, biopsy might show a germinomatous tumor with large polygonal cells mixed with lymphocytes. If so diagnose a benign germinoma.

Benign germinoma8:00–8:11

Malignant germ cell tumor8:11–8:52

All right. Now, back to our tumor markers.
If either a FP or beta HCG is elevated, consider a malignant germ cell tumor which includes yolk sac tumors, choriocarcinomas, immature teratomas and embryonal cell carcinomas.
Very high. A FP levels are diagnostic of a yolk sac tumor also known as an endodermal sinus tumor.
Whereas very high beta hcg levels are diagnostic of choriocarcinoma. Both yolk sac tumors and choriocarcinomas are aggressive, nongerminomatous germ cell tumors that can be diagnosed using tumor markers alone.
However, if the A FP is equivocal or mildly elevated, proceed with a biopsy or resection with histology. If results demonstrate a germinomatous tumor with spindle cells and primitive embryonic appearing neuroepithelial cells.

Immature teratoma8:52–9:29

Your patient has an immature teratoma. Here's a high yield fact, teratomas contain all three germinal layers of tissue.
In malignant immature teratomas, the tissue is poorly differentiated but in benign mature teratomas, the tissue is well differentiated and can contain hair teeth and fat.

Embryonal cell carcinoma9:29–9:47

Similarly, if beta HCG levels are equivocal or mildly elevated, you'll need to perform a biopsy or resection. If histology demonstrates a nongerminomatous tumor with large cells and a high mitotic index diagnose embryonal cell carcinoma.

Posterior fossa mass9:47–10:35

All right. Now, let's go back to our assessment for ataxia if present, consider a posterior fossa mass and then look for hyperreflexia and clonus.
If there's no evidence of hyperreflexia or clonus, consider a cerebellar or fourth ventricle mass. In this case, the patient might report visual changes like double vision or nystagmus as well as facial weakness and a new head tilt.
Physical exam findings might include papilledema, nystagmus, cranial nerve palsies, torticollis, and hemiparesis. If the MRI confirms a posterior fossa mass, proceed with a biopsy or resection and obtain histology.

Pilocytic astrocytoma10:35–10:54

If the biopsy shows compact fibrillary tissue, mixed with cystic spongy areas and evidence of rosenthal fibers, diagnose pilocytic astrocytoma.
These benign tumors are the most common type of astrocytoma in Children and are usually found in the cerebellum. However, if histology reveals homer right rosettes and small round blue cells, possibly with foci of necrosis, diagnose medulloblastoma, which can be found in either the cerebellum or the fourth ventricle.

Medulloblastoma10:54–11:15

These malignant tumors are a type of primitive neuroectodermal tumors lastly, if histology demonstrates tumor cells with regular round to oval nuclei and perivascular pseudo rosettes.

Ependymoma11:15–11:47

Your patient has ependymoma. These tumors are derived from the ependymal cells lining the ventricles and are usually found in the fourth ventricle.
Here's another clinical pearl choroid plexus tumors. The most common brain tumors in Children under a year of age also arise in the ventricles and usually present with symptoms of increased ICP.
All right, let's finish by discussing patients with hyperreflexia and the clonus. Here consider a brain stem mass affected patients often report visual changes like double vision as well as swallowing and speech difficulties and infants or toddlers often demonstrate early handedness.

Diffuse intrinsic pontine glioma11:47–12:54

The exam typically reveals multiple cranial nerve palsies and crossed findings which are characterized by facial weakness on one side of the body and hemiparesis on the opposite side.
If MRI shows a diffuse expansive infiltrating, minimally enhancing mass in the pons, diagnose a diffuse intrinsic pontine glioma.
These tumors are diagnosed by MRI and because they cannot be surgically resected, they carry a poor prognosis. Here's your last high yield fact, several familial syndromes are associated with brain tumors including neurofibromatosis types.
One and two. Von Hippel Lindau tuberous sclerosis and Lee Fraumeni syndrome.
All right. It's a quick recap brain tumors often present with symptoms related to tumor location, localized neurologic dysfunction or increased intracranial pressure.

Review12:54–13:43

Hemispheric tumors include glioblastoma, multiforme and primitive neuroectodermal tumors. Examples of midline tumors include suprasellar craniopharyngiomas, pineal masses like pineal parenchymal tumors and germ cell tumors such as benign germinomas yolk sac tumors, choriocarcinomas, immature teratomas and embryonal cell carcinomas.
Finally, posterior fossa tumors include pilocytic astrocytoma, medulloblastoma, ependymoma and diffuse intrinsic pontine glioma