Pediatric Brain Tumors Flashcards

1
Q

Your pediatric pt has a brain tumor. Where are you most likely to find it?

A

Infratentorial (cerebellum and brainstem)

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2
Q

What is the most common pediatric solid tumor?

A

Brain tumor! Second to all cancer only after Leukemia

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3
Q

What is a PNET?

A

2nd most common tumor in kids.

It is a SUPRAtentorial medulloblastoma

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4
Q

MC brain tumor in kids?

A

Astrocytoma (same as for adults, except infratentorial as opposed to hemispheric in adults)

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5
Q

List some genetic aberration that predispose peds pts to brain tumors of certain varieties.

A

Tuberous Sclerosis Ch.9/16- TSC1/2- Subependymal Giant Cell astrocytoma, Cortical tubers

NF1 Ch. 17- Glioma (optic nerve)

NF2- Ch. 22- bilateral acoustic schwannoma

VHL Ch. 3- hemangioma

Turcott syndrome (APC)- Medulloblastoma + GBM

Cowden (xPTEN= ^mTOR)- dysplastic gangliocytoma in cerebellum

Nevoid basal cell carcinoma/Gorlin synd (Ch. 9 PTCH)- Medulloblastoma

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6
Q

Describe the age classifications of various tumor locations.

A

11 yo: Supra/Infratentorial (including midline)- glioma, PNET, medulloblastoma, germ cell

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7
Q

Name the different glial tumor types.

A

Astrocytoma, oligodentrocytoma, ependymoma, choroid plexus tumors, GBM

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8
Q

BEST way to look for tumor?

A

MRI > CT&raquo_space; Bone scan (for mets)

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9
Q

Kid has a supratentorial tumor. What symptoms do you expect?

A

Hemiparesis, seizures

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10
Q

Kid has a midline tumor. What symptoms do you expect?

A

Endocrinopathies- compression of hypothalamus, pituitary

Hydrocephalus- compression of ventricular system (early AM headache, sundowning, bulging fontanelle)

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11
Q

Kid has an infratentorial tumor (MC). What symptoms do you expect?

A

Increased ICP due to compression of 4th ventricle
—> papilledema (blurring of optic disk margins) first sign, then —> sundowning/bulging fontanelle if delayed intervention

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12
Q

Kid has a brainstem tumor. What symptoms do you expect?

A

Diplopia, Dysarthria, Dysphagia- due to loss of CNs
Crossed weakness- due to lesion rostral to decussation
Lethargy, v respirations, coma. DON’T FUCK W/ THE BRAINSTEM

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13
Q

In many pediatric tumors, the MAPK pathway is deranged. Some derangements are preferentially found in certain parts of the brain and will this present with certain symptoms. Describe these.

A

BRAF fusion- Cerebellar tonsils

BRAF v600E- extracerebellar tumors

NF1- optic pathways (remember?! NF1 - optic nerve glioma)

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14
Q

You see hair-like projections radiating from neoplastic cells. What are these called and what type of tumor are they hallmarks of?

A

Rosenthal fibers, characteristic of Juvenile Pilocystic Astrocytoma

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15
Q

How do you treat a low grade pediatric tumor?

A

Resect that shit and radiate/chemo to be sure it is gone.

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16
Q

What are some serum markers for medulloblastoma?

Is it considered to be highly malignant?

A

TrkC, Erb, C-myc, Neurotrophinin

HIGHLY MALIGNANT primitive tumor

17
Q

What are the signalling pathway derangements that lead to medulloblastoma?

A

SHH + Wnt activity (BAD)

SHH active —> inactive PTCH—> ^ Gli2 to nucleus for transc.

Wnt active—> active frizzled—> no degradation of B-catenin

18
Q

What WHO grade is medulloblastoma?

Describe the molecular determination of prog. based on what pathways are active/inactive.

A

Grade IV (BAD)
SMO/Wnt active- Good progn.
C-myc- bad prognosis

19
Q

How does medulloblastoma look on histo?

A

Blue staining cells in a circle (Homer-Wright Rosettes)

20
Q

How do we tx medulloblastoma?

A

surgery + craniospinal radiation

21
Q

You see a tumor of the brainstem encasing the basilar artery. What tumor is this? How do we tx it?

A

Diffuse Intrinsic Pontine Glioma

Surgery CONTRINDICATED. Radiotx for amelioration. No cure.

22
Q

What is the classic triad of Diffuse Intrinsic Pontine Glioma?

A

CST signs (hemiparesis, weakness), Ataxia, CN 6, 7, 8 signs due to location @ pontomedullary junction

23
Q

Characteristic histology of ependymomas?

A

perivascular pseudorosettes, true rosettes

24
Q

We delay radiation tx until what age, due to the pediatric pt’s developing CNS?

A

3yo, but ideally 7