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17 Cards in this Set
- Front
- Back
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what tumors are gliomas?
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astrocytomas
oligodendrogliomas ependymomas |
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Four major types of astrocytoma and grade
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grade 1: pilocytic astrocytoma
grade 2: diffuse fibrillary astrocytoma grade 3: anaplastic astrocytoma grade 4: glioblastoma |
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tumor cells infiltrate normal tissue dx?
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diffuse fibrillary astrocytoma
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foamy macrophages dx?
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consider benign tumefactive lesion like acute MS plaque - otherwise ddx astrocytoma! also look for reactive gemistocytic astrocytes scattered
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what IHC is positive in astrocytic processes of astrocytoma?
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GFAP
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diagnostic features of glioblastoma
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necrosis (serpentine, pseudo-palisading)
endothelial cell prolif (VEGF, at least 2 layers, can be glomeruloid) |
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what is gliomatosis cerebri?
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multiple foci of infiltration by astrocytoma; aggressive (grade III)
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low-grade astrocytoma genetics
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p53 mut
PDGFa and PDGFRa overexpression |
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high grade astrocytoma genetics
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RB
p16/CDKNaA possibly chr19 TSG MDM2 EGFR |
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what is secondary glioblastoma?
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occurs in younger pts w h/o low grade astrocytoma; p53,PDGFa
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why is there edema in astrocytoma?
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leaky neovessels, espec in high grade
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role of MGMT in astrocytoma therapy?
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Methylation of the promoter for the gene encoding the DNA repair enzyme MGMT predicts responsiveness to DNA alkylating drugs
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pilocytic astrocytoma
age location grade |
pediatric
cerebellum (also perventricular and optic n) grade 1 |
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pilocytic astrocytoma path
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cystic, hairlike GFAP+ processes forming dense meshwork; often biphasic (microcystic and fibrillary), narrow infiltrative border (centripetal); vascular; Rosenthal bodies+, eosinophilic granular bodies+
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pilocytic astrocytoma genetics
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only rare p53 muts
if assoc'd w/NF1, has fxnl loss of neurofibromin (not in sporadic) |
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pleomorphic xanthoastrocytoma
age location grade |
pedi
temporal lobe (present w/seizure) grade 2 usually |
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pleomorphic xanthoastrocytoma path
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neoplastic +/-bizarre astrocytes
degree of nuclear atypia can be extreme, but abundant reticulin deposits, relative circumscription, and chronic inflam,no necrosis and no mitotic activity |
