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51 Cards in this Set
- Front
- Back
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CNS tumor epidemiology
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1.4% of total tumors
10% of these tumors are in children -2nd most popular children's tumor Incidence increases with age |
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Primary vs secondary tumors
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Around 50% of nervous system tumors are
primary ▫ Arise from cells intrinsic to the nervous system Remaining 50% are secondary / metastatic ▫ Originate from other organ systems ▫ Lung is the most common source |
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Most common malignant and benign CNS tumors
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Malignant:
-Primary: --Children: medulloblastoma --Adults: glioblastoma -Secondary: --Adults: lung carcinoma Benign -Children: pilocytic astrocytoma -Adults: meningioma |
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Inherited neoplastic syndromes
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Account for 1% of cases
Neurofibromatosis 1 -Neurofibroma Neurofibromatosis 2 -Schwannoma Tuberous sclerosis -SEGA Von Hippel Lindau -Hemangioblastoma Li Fraumeni -Gliomas |
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Radiation risk factor
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• Therapeutic radiation significantly increases the
risk for CNS tumors (upwards of 20-fold) •Types of tumors induced by radiation ▫ Meningioma (most common) ▫ Gliomas • Length of time required ▫ 8-10 years after radiation exposure |
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Immunosuppression risk factor
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• Immunosuppression is strongly associated with
primary CNS lymphoma ▫ AIDS patients (3600-fold increase in risk) ▫ Transplant patients • Most primary CNS lymphomas are high-grade and of B-cell origin ▫ Ebstein-Barr virus (EBV) is implicated in most cases |
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Signs and symptoms of CNS tumors
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• Most common are headaches, seizures, and
altered mental status • May get localized neurological deficits depending on tumor location |
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Radiologic features and enhancement patterns of CNS tumors
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▫ Most cystic tumors are low grade
▫ Most ring-enhancing tumors are high grade |
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Intra vs Extra-axial tumors
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• Intra-axial
▫ Tumors that arise within the parenchyma of the nervous system (brain, spinal cord, etc.) • Extra-axial ▫ Tumors that arise in the coverings (meninges) of the brain and spinal cord |
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Supratentorial vs Infratentorial
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• Supratentorial
▫ Compartment above the tentorium (cerebrum) ▫ Most adult tumors occur in this location • Infratentorial ▫ Compartment below the tentorium (cerebellum and brainstem) ▫ Most pediatric tumors occur in this location |
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Major categories of neoplasia
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• Glial tumors (gliomas)
• Neuronal tumors • Embryonal (primitive) tumors • Meningiomas • Nerve sheath tumors |
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Histologic grading
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• Assessment of the degree of differentiation
▫ How well the tumor resembles the cell / tissue of origin • Low grade tumors ▫ More closely resemble the cell / tissue of origin ▫ Better prognosis • High grade tumors ▫ Poor resemblance to the tissue of origin ▫ Worse prognosis • Four grades ▫ Grades I, II, III, and IV • Higher number = worse prognosis • High cellularity • Nuclear pleomorphism • High mitotic activity • Vascular proliferation • Necrosis |
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Astrocytoma main categories
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• (1) Diffuse astrocytomas
▫ Highly infiltrative ▫ Cannot be completely resected • (2) Circumscribed astrocytomas ▫ Minimal brain infiltration ▫ Can be completely resected |
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Diffuse astrocytoma: prevalence, age and gender, location
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• General
▫ Most common category of astrocytoma in adults • Age and gender ▫ Adults > children ▫ Male = female • Location ▫ Cerebrum (most common) |
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Diffuse astrocytoma: imaging
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• Low grade --> non-enhancing
• High grade --> enhancing |
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Diffuse astrocytoma grade II
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• Also known as “low grade astrocytoma”
• Represent ~10% of diffuse astrocytomas • Peak incidence between ages 30-40 years • Non-enhancing on imaging • Key pathologic features ▫ Hypercellular ▫ Nuclear atypia ▫ No mitotic activity, vascular proliferation, or necrosis |
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Diffuse astrocytoma grade III
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• Also known as “anaplastic astrocytoma”
• Represent ~20% of diffuse astrocytomas • Peak incidence between ages 40-50 years • Patchy enhancement on imaging • Key pathologic features ▫ Hypercellular ▫ Nuclear atypia ▫ Mitotic activity ▫ No vascular proliferation or necrosis |
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Diffuse astrocytoma grade IV
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• Also known as “glioblastoma”
• Represent ~70% of diffuse astrocytomas ▫ Most common primary malignant CNS tumor in adults • Peak incidence between ages 50-60 years • Ring enhancement on imaging • Key pathologic features ▫ Hypercellular ▫ Nuclear atypia ▫ Mitotic activity with vascular proliferation and/or necrosis |
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Genetics of diffuse astrocytomas
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TP53 mutation
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Prognosis for diffuse astrocytomas
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▫ Grade II: 6-8 years
▫ Grade III: 2-3 years ▫ Grade IV: 1 year ▫ Histologic grade ▫ Patient age ▫ Extent of surgical resection ▫ Performance status |
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Pilocytic astrocytoma: incidence, age and gender, location
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• Incidence
▫ Most common primary benign CNS tumor in children ▫ Account for 5-6% of gliomas • Age and Gender ▫ Children > adults (usually present before age 20) ▫ Male = female • Location ▫ Most common site is the cerebellum |
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Pilocytic astrocytoma: imaging, pathology, grade
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• Imaging
▫ Well circumscribed ▫ Cystic with a contrast enhancing mural nodule • Pathology ▫ Biphasic growth pattern (compact and loose) ▫ Rosenthal fibers ▫ Eosinophilic granular bodies ▫ Hyalinized blood vessels • Grade ▫ WHO grade I |
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Pilocytic astrocytoma: genetic susceptibility
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▫ Neurofibromatosis type 1 (NF1; 17q11)
• Neurofibromas • Malignant peripheral nerve sheath tumors • Pilocytic astrocytomas (optic nerve) |
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Pilocytic astrocytoma: prognosis
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▫ Generally, prognosis is good
▫ Extent of resection is an important factor ▫ Gross total resection: 10-year survival is around 90% ▫ Partial resection: 10-year survival is around 50% |
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Oligodendrogliomas: incidence, age and gender, location
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• Incidence
▫ Account for 5% of gliomas ▫ Less common than astrocytomas • Age and gender ▫ Adults > children ▫ Male = female • Location ▫ Frontal lobe is the most common location |
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Oligodendrogliomas: infiltrating tumors, grade
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• Infiltrating tumors
▫ No circumscribed forms • Grade ▫ Span from low (II) to high grade (III) ▫ Low grade tumors may “progress” to high grade tumors |
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Oligodendrogliomas grade II
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• Also known as “low grade oligodendroglioma”
• Represent ~75% of oligodendrogliomas • Peak incidence between ages 40-45 years • Usually non-enhancing on imaging • Key pathologic features ▫ Hypercellular ▫ Round nuclei & perinuclear clearing (fried eggs) ▫ Arborizing microvasculature (chicken wire) ▫ Low mitotic rate ▫ No vascular proliferation or necrosis |
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Oligodendrogliomas grade III
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• Also known as “anaplastic oligodendroglioma”
• Represent ~25% of oligodendrogliomas • Peak incidence between ages 45-50 years • Usually enhancing on imaging • Key pathologic features ▫ Hypercellular ▫ Round nuclei & perinuclear clearing (fried eggs) ▫ Arborizing microvasculature (chicken wire) ▫ High mitotic rate, vascular proliferation, necrosis |
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Genetics of oligodendroglioma
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1p/19q deletions (70-80%)
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Prognosis for oligodendrogliomas
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• Prognostic factors
▫ Histologic grade ▫ Genetic alterations (loss of 1p/19q is favorable) ▫ Patient age ▫ Extent of surgical resection ▫ Performance status • Grade and median survival ▫ Grade II: 11-12 years ▫ Grade III: 4-5 years (greater if loss of 1p/19q) |
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Ependymomas: incidence, age and gender, locations
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• Incidence
▫ Account for 10% of pediatric brain tumors • Age and gender ▫ Predominantly tumors of children ▫ Median age for posterior fossa tumors = 6-7 years ▫ Male = female • Location ▫ Arise from the wall of the ventricles ▫ Children --> Posterior fossa (4th ventricle / cerebellum) ▫ Adults --> cerebrum and spinal cord |
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Ependymomas: imaging and pathology
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• Imaging
▫ Circumscribed ▫ Varying amount of enhancement ▫ Often obstruct the ventricles and result in hydrocephalus • Pathology ▫ Circumscribed, non-infiltrative tumors ▫ Hypercellular ▫ Monomorphic cells ▫ Perivascular pseudorosettes |
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Ependymomas grade
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▫ Span from low (I) to high grade (III)
▫ Most are grade II ▫ Criteria for high grade not well defined |
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Ependymomas genetics
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• Genetics
▫ Loss or deletions of chromosome 22 (most common) ▫ Targets the NF2 gene (22q12) |
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Ependymomas prognostic factors
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▫ Patient age
• Children have a worse prognosis than adults • 5-year survival 50% for children and 57% for adults ▫ Tumor location • Spinal ependymomas do the best • Posterior fossa tumors do the worst ▫ Cerebrospinal dissemination (worse prognosis) ▫ Extent of resection ▫ Histologic grade (inconsistent results) |
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Ganglioglioma: incidence, age and gender, location
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• Incidence
▫ Account for around 1% of primary brain tumors • Age and gender ▫ More common in children and young adults ▫ No gender predilection • Location ▫ Temporal lobe (most common) ▫ Often associated with seizures |
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Ganglioglioma: imaging, histology, grading
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• Imaging
▫ Cystic with a contrast-enhancing mural nodule • Histology ▫ Mixed neoplastic ganglion cells and glial cells ▫ Rosenthal fibers and eosinophilic granular bodies • Grading ▫ WHO grade I |
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Ganglioma: genetics and prognosis
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• Genetics
▫ No consistent genetic alterations • Prognosis ▫ Good prognosis in most cases ▫ Recurrence free survival at 7.5 years is 94% |
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Primitive tumors overview
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• Also known as "embryonal" tumors
• Neuroectodermal origin • Little or no neuronal or glial differentiation • Composed of primitive or embryonal cells • Fit into the category of "small blue cell tumors" • Usually occur in children • Medulloblastoma is the most common example |
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Medulloblastoma: general, incidence, age and gender
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• General
▫ Malignant tumors that are thought to arise from undifferentiated stem cells in the cerebellum • Incidence ▫ Account for 20% of brain tumors in children ▫ Most common primary malignant CNS tumor in children • Age and gender ▫ Children, peak incidence at around 7 years of age ▫ More common in males (65%) |
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Medulloblastoma: location, radiology, histology, grade
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• Location
▫ Arise in the posterior fossa / cerebellum • Radiology ▫ Well-circumscribed, contrast-enhancing ▫ Often nodular • Histology ▫ Densely cellular (small blue cell tumor) ▫ Irregular, hyperchromatic nuclei ▫ Scant cytoplasm ▫ May form neuroblastic (Homer Wright) rosettes • Grade ▫ WHO grade IV |
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Medulloblastoma: genetics, prognosis, unfavorable prognostic factors
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• Genetics
▫ Isochomosome 17q (30-40% of cases) • Prognosis ▫ Modern therapies (chemotherapy and radiation) have greatly improved prognosis ▫ 5-year survival is around 60-70% • Unfavorable prognostic factors ▫ Age < 3 years ▫ Incomplete surgical resection ▫ CSF dissemination |
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Meningiomas: general, incidence, age and gender
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• General
▫ Meningothelial (arachnoid) cell neoplasms ▫ Grow along the inner surface of the dura • Incidence ▫ Account for 25% of primary intracranial tumors ▫ Most common primary extra-axial tumor • Age and gender ▫ Adults (peak incidence 40-70 years) ▫ More common among females (M:F = 2:3) • Spinal meningiomas show a marked female predominance ▫ Males are more likely to have higher grade tumors |
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Meningiomas: location, imaging, histology
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• Location
▫ Most occur over the cerebral convexities • Imaging ▫ Dural-based mass (extra-axial) ▫ Contrast enhancing • Histology ▫ Whorls and psammoma bodies (calcifications) |
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Meningiomas: grades and criteria
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• Grades
▫ Grade I (90%): Benign ▫ Grade II (7%): Atypical ▫ Grade III (3%): Malignant • Grading criteria (partial list) ▫ Cellularity ▫ Nuclear pleomorphism ▫ Mitotic activity ▫ Necrosis ▫ Brain invasion |
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Meningioma: genetics
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▫ Associated with deletions of chromosome 22
▫ Target is the NF2 gene on 22q12 ▫ Multiple meningiomas in patients with NF2 |
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Meningioma: prognosis and recurrence
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• Prognosis
▫ Major prognostic factors are (1) grade and (2) extent of resection ▫ Higher grade tumors frequently recur ▫ Incompletely resected tumors often recur • Recurrence rates according to grade ▫ Grade I: 7-25% ▫ Grade II: 29-52% ▫ Grade III: 50-94% (median survival < 2 years) |
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Schwannoma: general, incidence, age and gender
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• General
▫ Benign tumors that arise from Schwann cells • Neural crest derived cells that form myelin sheaths for peripheral nerves • Incidence ▫ Common tumors ▫ Account for 30% of spinal tumors and 8% of intracranial tumors • Age and gender ▫ Adults (peak incidence 40-50 years) ▫ Male = female |
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Schwannoma: location, imaging
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• Location
▫ Most common location within the nervous system is the cerebellopontine angle • 8th cranial nerve ▫ Called “acoustic neuroma” or “vestibular neuroma” • Imaging ▫ Well-circumscribed, contrast-enhancing ▫ Occasionally cystic |
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Schwannoma: histology and grade
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• Histology
▫ Mixed hypercellular (Antoni A pattern) and hypocellular (Antoni B pattern) growth ▫ Nuclear palisading (Verocay bodies) ▫ Hyalinized blood vessels • Grade ▫ WHO grade I tumors |
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Schwannoma: genetics and prognosis
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• Genetics
▫ Associated with mutations of the NF2 gene (22q12) ▫ Neurofibromatosis type 2 • Autosomal dominant disorder • Germline mutations in the NF2 gene • Develop bilateral vestibular schwannomas • Also get meningiomas and gliomas • Prognosis ▫ Good (infrequent recurrence) |
