Pediatric Neurosurgical NeuropathologyPediatric 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. 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
Brain tumors: introBrain tumors: intro
Intracranial neoplasms– Primary– Secondary
»Metastatic»Local invasion
Tumors of the spinal cord
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
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
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
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
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)
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
Pilocytic astrocytomasPilocytic astrocytomas
Tumor of cerebellum, often with cyst, biphasic, Rosenthal fibers, piloid cells
Astrocytoma - high gradeAstrocytoma - 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:
– Densely cellular, with marked nuclear pleomorphism– Numerous mitoses– Endothelial proliferation– Necrosis with pseudopallisading
Glioblastoma (grade IV)Glioblastoma (grade IV)
Less common in children than adults, typical pathology (necrosis with psuedopallisading)
Pontine gliomaPontine glioma
Diffuse expansion of pons, usually high grade astrocytoma (III-IV)
MedulloblastomasMedulloblastomas PNET of posterior fossa in children Histologic appearance:
– Densely cellular “small blue cell tumor”– Numerous mitoses– Apoptotic (karyorrhectic) cells– Endothelial proliferation– Necrosis– neuronal or glial differentiation
» Homer Wright rosettes» GFAP positive cells
MedulloblastomaMedulloblastoma
Mass arising in roof of fourth ventricle
Homer Wright rosettes
EpendymomaEpendymoma
Mass arising in floor of fourth ventricle
Perivascular pseudorosettes
MeningiomasMeningiomas
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)
MeningiomasMeningiomas
Extra-axial tumor, meningothelial cells, whorls and psammoma bodies
GangliogliomaGanglioglioma
Cerebrum, cervicomedullary, often with cystic component
Increased numbers of neurons (some binucleate) and increased glial cells (usually astrocytic)
CraniopharyngiomaCraniopharyngioma
Heterogeneous, cystic mass in suprasellar region Basiloid layer, stellate reticulum, “wet” keratin,
often calcified
Choroid plexus papillomaChoroid plexus papilloma
Lateral ventricle in children (fourth ventricle in adults)
Germ cell tumorsGerm cell tumors
Pineal - 99% males, most are germinomas Suprasellar - often mixed germ cell tumor,
50% female Tertomas are rare
Germinoma Teratoma
Metastatic tumorsMetastatic 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 tumorsOther 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 syndromesHereditary syndromes Neurofibromatosis type I
– 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