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102 Cards in this Set
- Front
- Back
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where are 70 percent childhood CNS tumors |
arise in posterior fossa
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where are the majority of adult CNS tumors
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above tentorium
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why is it not feasible to resect glial neoplasms
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infiltrative behavior - resection would compromise neurologic fxn
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what tumors are included in gliomas (most common group of primary brain tumors)
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astrocytomas, oligodendrogliomas, and ependymomas
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infiltating astrocytomas
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80% primary brain tumors in adults, ago of onset 40-60; usual in cerebral hemispheres, also in cerebellum, brainstem, or spinal cord
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symptoms of infiltrating astrocytoma
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seizures, headaches, focal neurologic deficits related to anatomic site
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grades of infiltating astrocytomas
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I/IV pilocytic astocytoma, II/IV difuse astrocytoma, III/IV anaplastic astrocytoma, IV/IV glioblastoma
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gross appearance of infiltrating astrocytoma
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poorly defined, gray, infiltrative tumor that expands and distorts the invaded brain; few cm to half hemisphere
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microscopic infiltrating astrocytoma appearance
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mild to moderate increase in glial cellularity, variable nuclear pleomorphism, intervening feltwork of fine GFAP-positive astrocytic processes
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anaplastic astrocytomas (III/IV)
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regions more densely cellular and have greater nuclear polymorphisms; mitotic figures
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glioblastoma (IV/IV)
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variation from area to area; additional features of necrosis and vascular or endothelial cell proliferation
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genetic alterations in low gradde astrocytomas
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p53 and overexpression of PDGF-A and its receptor
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genetic alterations for transition into higher grade astrocytoma
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tumor suppresor genes RB and p16/CDKNaA
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net affect of genetic alterations in astrocytomas
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activate RAS and PI-3 kinase and inactivate p53 and RB
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radiologic studies of astrocytomas
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mass effect as well as changes in the brain adjacent the tumor (edema)
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clinical outcome of infiltrating astrocytoma
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poor
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pilocytic astrocytoma
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benign behavior; in children and young adults; located in cerebellum and maybe floor and walls of 3rd ventricle
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macro/microscopic exam of pilocytic astrocytomas
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cystic; bipolar cells with thin, long 'hairlike' processes GFAP-positive and form dense fibrillary meshworks; narrow infiltrative border with surrounding brain
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pleomorphoc Xanthoastrocytoma
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tumor often in temporal lobe of children/yound adults with history of seizures
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morphology of pleomorphoc Xanthoastrocytoma
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abundant reticulin deposits, relative circumscription, and chronic inflammatory cell infiltrates; absence of necrosis and mitotic activity; grade II/IV
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brainstem glioma
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intrinsic pontine gliomas most comon with aggressive course and short survival; divided into low-grade diffuse fibrillary astrocytomas and glioblastoma
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oligodendroglioma
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most often in cerebral hemispheres with predilection for white matter; 5-15% of gliomas; II/IV
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gross morphology of oligodendroglioma
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well-circumscribed, gelatinous, gray, often with cysts, focal hemorrhage, calcification
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microscopic oligodendroglioma appearance
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sheets of regular cells with spherical nuclei containing granular chromatin surrounded by a clear halo of cytoplasm
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anaplastic oligodendrogliomas (III/IV) morphology
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increased cellular density, nuclear anaplasia, increased mitotic activity, necrosis; higher gade indistinguishable from glioblastoma
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most common genetic alteration in oligodendeoglioma
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loss of heterozygosity of chomosomes 1p and 19q; no EGFR gene amplification
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ependymoma
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arise next to ependyma-lined ventricular system; spinal cord in adults and 4th ventricle in kids; most II/IV
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when are ependymomas seen frequently
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neurofibromatosis type 2
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4th ventricle ependymomas
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solid/papillary masses extending from floor, well demarcated from brain
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microscopic ependymoma appearance
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regular, round/oval nucleus and abundant granular chromatin, variably dense fibrillary background btwn nuclei; gland-like round to elongated structures; perivascular pseudorosettes
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perivascular pseudorosettes
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tumor cells around vells with intervening zone consisting of thin ependymal processes directed toward wall of vessel
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anaplastic ependymoma
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increased cell density, high mitotic rate, areas of necrosis, less evident differentiation
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myxopapillary ependymoma
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lesion occur in filum terminale of spinal cord and contain papillary elements in a myxoid background
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subependymomas
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solid, sometimes calcified slow growing nodulles attached to ventricular lining and protruding into the ventricle; generally incidental indings at autopsy or imaging
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choroid plexus papillomas
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most often lateral ventricles (kids) and 4th ventricle (adults); marked papillary growths; hydrocephalus
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colloid cyst of the 3rd ventricle
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non-neoplastic lesion in young adults; attached to 3rd ventricle roof; noncommunicating hydrocephalus
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gangliomas
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most slow growing, often presents as seizure disorder, generally in temporal lobe
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dysembryoplastic neuroepithelial tumor
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rare, low grade tumor of childhood presenting as seizure disorder; good prognosis after resection; superficial temporal lobe
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lesions that show both the specific element and a glial component
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complex
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central neurocytoma
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typically low-grade neuronal neoplasm within ventricular system; even spaced, round, uniform nuclei and often islands of neuropil - resemble oligodendroglioma
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medulloblastoma
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children, only in cerebellum; tumor largely undifferentiated
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morphology of medulloblastoma
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well circumscribed, gray, friable
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microscopic medulloblastoma appearance
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extremely cellular with sheets of anaplastic cells; individual cells small with scant cytoplasm and hyperchromatic nuclei crescent shaped or elongated; mitoses abundant
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desmoplastic variant of medulloblastoma
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areas of stromal response marked by collagen and reticulin deposition and nodules of cells forming 'pale islands'
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genetic alteration in medulloblastomas
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loss of material from 17p; MYC amplification = aggressive clinical course
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atypical teratoid/rhabdoid tumor
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highly malignant of young children; posterior fossa and supratentorial compartments
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morphology of atypical teratoid
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large, soft consistency spread along surface of brain; rhabdoid cells have eosinophilic cytoplasm, sharp cell borders, and eccentrically located nuclei
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genetic alterations in atypical teratoid
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chromosome 22 is a hallmark - hSNF5/INI1 which encodes a protein that is a part of a large complex involved in chromatin remodeling
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outcome of atypical teratoid
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live less than 1 year after diagnosis
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primary CNS lymphoma
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most common in immunosuppresed; most B-cell origin; Epstein-Barr virus; aggressive
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morphology of primary CNS lymphoma
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multiple lesions involving gray matter and white matter, periventricular spread; extensive areas of central necrosis; 'hooping'
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intravascular lymphoma
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unusual lymphoid malignancy where tumor cells grow intraluminally within small vessels; microscopic infarcts occur
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germ cell tumors
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resemble gonadal germ cell tumors and follow similar course
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pineal parenchymal tumors mutations
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germline mutations in RB (trilateral retinoblastoma)
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meningiomas
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benign tumors of adults attached to dura; I/IV
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what other tumors can grow as dural-based masses
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metastases, solitary fibrous tumors, range of poorly differentiated sarcomas
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morphology of meningiomas
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rounded masses with well-defined dural bases that compress underlying brain, but easily separated from it
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syncytial (meningothlial) meningiomas
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whorled clusters of cells that sit in tight groups without visible membranes
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fibroblastic meningiomas
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elongated cells and abundant collagen deposition btwn them
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transitional meningiomas
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share features of syncytial and fibroblastic types
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psammomatous meningiomas
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psammoma bodies - apparently formed from calcification of the syncytial nests of meningial cells
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secretory meningiomas
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PAS-positive intracytoplasmic droplets and intracellular lumans by elecron microscopy
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microcystic meningiomas
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loose, spongy appearance
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what classified a meningioma as atypical
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4 or more mioses per 10 high powered fields; require excition and radiation; II/IV
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cytogenetic abnormality in meningiomas
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loss of chromosome 22, especially long arm; common in NF2
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meningiomas and pregnancy
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contain progesterone receptors and may grow more quickly during pregnancy
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most common sites that metastisize to CNS
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lung, breast, skin, kidney, GI = 80% of metastases
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subacute cerebellar degeneration in encephalomyelitis
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destruction of Purkinje cells, gliosis, and mild inflammatory infiltrate
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limbic encephalitis in encephalomyelitis
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subacute dementia and marked by perivascular inflammatory cuffs, microglial nodules, some neuronal loss, and gliosis - resembles infectious process
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eye movement disorders in encephalomyelitis
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opsoclonus with other evidence of cerebellar and brainstem dysfunction
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subacute sensory neuropathy in encephalomyelitis of PNS
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loss of sensory neurons from dorsal root ganglia in association with lyphocytic inflammation
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Lambert-Eaton myasthenic syndrome in encephalomyelitis of PNS
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antibodies against voltage gated Ca2+ channels in presynaptic elements of neuromuscular jxn
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peripheral nerve sheath tumors
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from schwann, perineurial cells, and fibroblasts; S-100 antigen
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schwannoma
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arise from neural crest derived schwann cell and cause symptoms via compression; NF2 association
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what occurs to cells in absence of EGFR
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hyperproliferation in response to GFs
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morphology of schwannomas
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well-circumscribed, encapsulated masses attached to nerve, but can be separated from it; firm, gray masses, may be cystic
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Antoni A pattern of growth
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elongated cells with cytoplasmic processes arranged in fascicles in areas of moderate to high cellularity and scant stromal matrix
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Antoni B pattern of growth
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less densely cellular and consists of loose meshwork of cells, microcysts, and myxoid stroma
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where do schwannomas occur within the cranium
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attached to CN8 at cerebellopontine angle "acoustic neuroma"; also branches of trigeminal
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Neurofibroma
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discrete localized mass as cutaneous neurofibroma or in peripheral nerve as solitary neurofibroma; NF1 association if multiple; mostly cosmetic concern if cutaneous
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cutaneous neurofibroma morphology
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dermis and subcutaneous fat; well-delineated but encapsulated composed of spindle cells
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plexiform neurofibroma morphology
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anywhere along nerve, usually multiple; can't separate from nerve, poorly defined margins; contain schwann cells, inflammatory cells, large multipolar fibroblastic cells; areas of collagen bundles, axons within tumor
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What is the fxn of the NF1 gene product
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stimulates activity of a GTPase that inhibits RAS activity
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malignant peripheral nerve sheath tumor
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highly malignant, locally invasive, multiple recurrences and metastatic spread; medium to large nerves; 50% NF1 association
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malignant peripheral nerve sheath tumor morphology
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poorly defined tumor masses along axis of parent nerve and invade adjacent soft tissues
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malignant peripheral nerve sheath tumor microscopic morphology
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mitoses, necrosis, extreme nuclear anaplasia common; resemble other tumor patterns
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Cowden syndrome
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dysplastic ganglioglicytoma of cerebellum caused by PTEN mutation
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what does PTEN mutation result in
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increased activity of AKT and mTOR pathways
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Li-Fraumeni syndrome
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medulloblastomas caused by mutations in p53
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Turcot syndrome
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medulloblastoma or glioblastoma caused by APC or mismatch repair gene mutations
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Gorlin syndrome
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medulloblastoma caused by PTCH mutation
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what does PTCH mutation cause
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up-regulation of SHH signaling pathways
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neurofibromatosis type 1
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autosomal dominant 1/3000; neurofibromas, gliomas of optic nerve, pigmented nodules of iris, cutaneous hyperpigmented macules
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neurofibromatosis type 2
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autosomal dominant resulting in range of tumors: 8th nerve schwannomas and muliple meningiomas most common, gliomas of spinal cord, nodular growth of schwann cells into spinal cord, meningioangiomatosis, glial hamartia; 1/40000-1/50000
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tuberous sclerosis complex
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autosomal dominant 1/6000; hamartomas and benign neoplasma of brain and other soft tissues; cortical tubers often epiliptogenic, hypopigmented areas, neoplasms/cysts in other organs
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mutation in tuberous sclerosis complex
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TSC1 on 9q34 and encodes hamartin, TSC2 at 16p13.3 encodes tuberin; proteins bind forming complex that inhibits kinase mTOR
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what is mTOR
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key regulator of protein synthesis and other aspects of anabolic metabolism
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morphology of tuberous sclerosis complex-cortical hamartomas
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firm areas of cortex like potatos; haphazardly arranged neurons; some large cells have appearances intermediate btwn glia and neurons
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Von Hippel-Lindau Disease
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autosomal dominant; hemangioblastomas and cyst involving pancreas, liver, kidneys, and pheochromocytoma; most comon in cerebellum and retina; 1/30000 to 1/40000
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gene associated with Von Hippel-Lindau Disease
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tumor suppresor gene on that encodes pVHL - component of ubiquitin ligase complex that down regulated hypoxia-induced factor 1
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HIF-1
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transcription factor involved in regulating expression of vascular endothelial GF erythropoirtin
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morphology of hemangioblastomas
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highly vascular neoplasms that occur as a mural nodule associated with large fluid-filled cyst
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