Pediatric Tumors

8/8/2019 Pediatric Tumors

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Pediatric Neurosurgical NeuropathologyPediatric Neurosurgical Neuropathology

Brain tumors are second only toleukemias in children

Brain tumors are the most common solidorgan tumor in children

70% of pediatric brain tumors are in theposterior fossa

Pilocytic astrocytoma

Medulloblastoma

Ependymoma


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CNS tumors: pediatric vs. adultCNS tumors: pediatric vs. adult

Adults: 70% of tumors are supratentorial

meningioma

pituitary adenoma

High grade astrocytoma Anaplastic astrocytoma (grade III)

Glioblastoma multiforme (grade IV astrocytoma)

Pediatric: 70% in posterior fossa

pilocytic astrocytoma (cerebellar astrocytoma)

medulloblastoma


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Brain tumors: introBrain tumors: intro

Intracranial neoplasms

Primary

Secondary Metastatic

Local invasion

Tumors of the spinal cord


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Primary brain tumors: introPrimary brain tumors: intro

Primary brain tumors are rare 2.5% of all cancer deaths

Second most common type of tumor in children

There are over 100 different brain tumors

Most common types Astrocytomas

Grades I-IV

Medulloblastomas

primitive neuroectodermal tumor-PNET

Meningiomas

Pituitary adenomas


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Clinical presentationClinical presentation

Clinical symptoms depend upon: Age, location, and type of tumor and grade

Symptoms may include: Increased intracranial pressure

secondary to obstruction of CSF at aqueduct

hydrocephalus (infants), headache, papilledema, vomiting

seizures

focal neurological deficits

hormonal changes (pituitary adenoma) visual changes (diplopia, field defects)

Pituitary adenoma - pressure on optic chiasm


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CNS tumors: diagnosisCNS tumors: diagnosis

Symptoms prompt neuroimaging

CT and MRI

intra-axial vs. extra-axial Location of tumor

contrast enhancement typical of high grade

also in some low grade, i.e., pilocytic astrocytomas


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CNS tumors: locationCNS tumors: location

Extra-axial

meningiomas

Cerebral hemispheres

grade II-III astrocytomas, GBM Crossing corpus callosum - GBM

optic nerve - pilocytic astrocytoma (NF-1)

Sella - Pituitary adenoma

Peri-III ventricle - Pilocytic astrocytoma, GBM


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CNS tumors: locationCNS tumors: location

posterior fossa (in children)

pilocytic astrocytoma

medulloblastoma

brainstem (pons)

pontine glioma (astrocytoma)

spinal cord

low-grade astrocytomas (grade I and II)


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Pilocytic astrocytomasPilocytic astrocytomas

Most common in children Grade I astrocytoma

Cerebellum (posterior fossa), optic nerve Thalamic, spinal cord, cerebral

Discrete, well circumscribed mass Often with associated cystic area

Contrast enhancing

Histologic appearance:

Biphasic: piloid cells and microcystic areas Rosenthal fibers

no mitoses


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Pilocytic astrocytomasPilocytic astrocytomas

Tumor of cerebellum, often with cyst,biphasic, Rosenthal fibers, piloidcells


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AstrocytomaAstrocytoma -- high gradehigh grade

Astrocytoma grade II and III are very, very rare inthe pediatric population

Grade IV - glioblastoma multiforme

Diffusely infiltrating glial tumor of cerebral

hemispheres Contrast enhancing tumor

Histological appearance: Densely cellular, with marked nuclear pleomorphism

Numerous mitoses Endothelial proliferation

Necrosis with pseudopallisading


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Glioblastoma (grade IV)Glioblastoma (grade IV)

Less common in children than adults, typicalpathology (necrosis with psuedopallisading)


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Pontine gliomaPontine glioma

Diffuse expansion of pons, usually highgrade astrocytoma (III-IV)


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MedulloblastomasMedulloblastomas

PNET of posterior fossa in children

Histologic appearance:

Densely cellular small blue cell tumor

N

umerous mitoses Apoptotic (karyorrhectic) cells

Endothelial proliferation

Necrosis

neuronal or glial differentiation Homer Wright rosettes

GFAP positive cells


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MedulloblastomaMedulloblastoma

Mass arising in roof offourth ventricle

Homer Wright rosettes


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EpendymomaEpendymoma

Mass arising in floor offourth ventricle

Perivascularpseudorosettes


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MeningiomasMeningiomas

Discrete non-invasive tumor

Extra-axial, pushes into brain

Attached to dura

H

yperostosis or invasion of skull common Histologic appearance:

Fibroblastic or menigothelial cells

Meningothelial whorls

Psammoma bodies Rare in children, may be intraventricular

(lateral ventricles)


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MeningiomasMeningiomas

Extra-axial tumor, meningothelial cells, whorls andpsammoma bodies


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GangliogliomaGanglioglioma

Cerebrum, cervicomedullary, often with cystic component

Increased numbers of neurons (some binucleate) and increased glial cells(usually astrocytic)


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CraniopharyngiomaCraniopharyngioma

Heterogeneous, cystic mass in suprasellar region Basiloid layer, stellate reticulum, wet keratin, often

calcified


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Choroid plexus papillomaChoroid plexus papilloma

Lateral ventricle in children (fourth ventriclein adults)


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Germ cell tumorsGerm cell tumors

Pineal - 99% males, most are germinomas Suprasellar - often mixed germ cell tumor, 50%

female

Tertomas are rare

Germinoma Teratoma


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Metastatic tumorsMetastatic tumors

The most common brain tumor in adults ismetastatic

Metastatic tumors are rare in children

The most common metastatic tumor in children isosteosarcoma

Local extension of malignant tumors of vertebralbodies (Ewings sarcoma) or paravertebral soft tissues(neuroblastoma) are not uncommon


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Other tumorsOther tumors S

ubependymal giant cell astrocytoma (S

EGA) Intraventricular tumor in Tuberous sclerosis

Desmoplastic infantile ganglioglioma (DIG)

Superficial cerebral tumor in infants

Dysembryoplastic neuroepithelial tumor (DNET)

Hamartomatous lesion associated with seizures Atypical teratoid rhabdoid tumor (ATR, AT/RT)

Infants, posterior fossa, very malignant

Eosinophilic granuloma

A type of Langerhans cell histiocytosis

Single discrete osteolytic lesion in skull Meningioangiomatosis

Hamartomatous superficial cerebral lesion associated withseizures


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Hereditary syndromesHereditary syndromes

Neurofibromatosis type I Caf-au-lait spots

Dermatofibromas, multiple

optic nerve gliomas, bilateral

plexiform neurofibroma Malignant peripheral nerve sheath tumor

Neurofibromatosis type II

bilateral acoustic neuroma

multiple meningiomas

ependymomas

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Pediatric Tumors