Pediatric Tumors - University of Pittsburgh
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Transcript Pediatric Tumors - University of Pittsburgh
Pediatric Neurosurgical Neuropathology
Brain tumors are second only to
leukemias in children
Brain tumors are the most common solid
organ tumor in children
70% of pediatric brain tumors are in the
posterior fossa
– Pilocytic astrocytoma
– Medulloblastoma
– Ependymoma
CNS 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
Brain tumors: intro
Intracranial neoplasms
– Primary
– Secondary
» Metastatic
» Local invasion
Tumors of the spinal cord
Primary 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
Clinical 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
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seizures
focal neurological deficits
hormonal changes (pituitary adenoma)
visual changes (diplopia, field defects)
» Pituitary adenoma - pressure on optic chiasm
CNS 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
CNS 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
CNS tumors: location
posterior fossa (in children)
– pilocytic astrocytoma
– medulloblastoma
brainstem (pons)
– pontine glioma (astrocytoma)
spinal cord
– low-grade astrocytomas (grade I and II)
Pilocytic astrocytomas
– Most common in children
– Grade I astrocytoma
– Cerebellum (posterior fossa), optic nerve
» Thalamic, spinal cord, cerebral
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Discrete, well circumscribed mass
Often with associated cystic area
Contrast enhancing
Histologic appearance:
» Biphasic: piloid cells and microcystic areas
» Rosenthal fibers
» no mitoses
Pilocytic astrocytomas
Tumor of cerebellum, often with cyst,
biphasic, Rosenthal fibers, piloid
cells
Astrocytoma - high grade
Astrocytoma grade II and III are very, very rare in
the pediatric population
Grade IV - glioblastoma multiforme
Diffusely infiltrating glial tumor of cerebral
hemispheres
Contrast enhancing tumor
Histological appearance:
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Densely cellular, with marked nuclear pleomorphism
Numerous mitoses
Endothelial proliferation
Necrosis with pseudopallisading
Glioblastoma (grade IV)
Less common in children than adults, typical
pathology (necrosis with psuedopallisading)
Pontine glioma
Diffuse expansion of pons, usually high
grade astrocytoma (III-IV)
Medulloblastomas
PNET of posterior fossa in children
Histologic appearance:
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Densely cellular “small blue cell tumor”
Numerous mitoses
Apoptotic (karyorrhectic) cells
Endothelial proliferation
Necrosis
neuronal or glial differentiation
» Homer Wright rosettes
» GFAP positive cells
Medulloblastoma
Mass arising in roof of
fourth ventricle
Homer Wright rosettes
Ependymoma
Mass arising in floor of
fourth ventricle
Perivascular
pseudorosettes
Meningiomas
Discrete non-invasive tumor
– Extra-axial, pushes into brain
– Attached to dura
– Hyperostosis or invasion of skull common
Histologic appearance:
– Fibroblastic or menigothelial cells
– Meningothelial whorls
– Psammoma bodies
Rare in children, may be intraventricular
(lateral ventricles)
Meningiomas
Extra-axial tumor, meningothelial cells, whorls and
psammoma bodies
Ganglioglioma
Cerebrum, cervicomedullary, often with cystic component
Increased numbers of neurons (some binucleate) and increased glial cells
(usually astrocytic)
Craniopharyngioma
Heterogeneous, cystic mass in suprasellar region
Basiloid layer, stellate reticulum, “wet” keratin, often
calcified
Choroid plexus papilloma
Lateral ventricle in children (fourth ventricle
in adults)
Germ cell tumors
Germinoma
Teratoma
Pineal - 99% males, most are germinomas
Suprasellar - often mixed germ cell tumor, 50%
female
Tertomas are rare
Metastatic tumors
The most common “brain” tumor in adults is
metastatic
Metastatic tumors are rare in children
The most common metastatic tumor in children is
osteosarcoma
Local extension of malignant tumors of vertebral
bodies (Ewing’s sarcoma) or paravertebral soft tissues
(neuroblastoma) are not uncommon
Other tumors
Subependymal giant cell astrocytoma (SEGA)
– 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 with
seizures
Hereditary syndromes
Neurofibromatosis type I
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Café-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