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107 Cards in this Set
- Front
- Back
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what does DNET stand for
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Dysembryoplastic Neuroepithelial Tumor
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Classic presentation of DNET
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10-30yo w refractory complex partial sz
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location and appearance of DNET
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nodular, cortical mass, low on T1, high on T2; hypodense on CT
a soap bubbly appearance can be seen in the periphery |
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cells contained in DNET
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astrocytes
oligodendroglial cells neurons |
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#1 extra-ax tumor
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meningioma
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who gets meningioma
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50-60yo women (hormonally sensitive)
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what are multiple meningiomas associated with
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NF
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most common locations of meningiomas
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parasaggital/convexity > sphenoid wing > olfactory groove > parasellar regiona
2-3% are in teh t-spine |
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cells that comprise meningiomas
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arachnoid cap cells (buried in choroid plexus)
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appearance of mening on MR and CT
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extra-axial with broad based dural tail
iso T1 and T2 hyperdense on CT with variable edema, homogeneous enhancement. associated with hyperostosis |
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pathophys of heterotopic grey matter
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as neurons migrate from germinal matrix to overlying cerebral cortex, journey can be interrupted --> trapped nests of GM deep within the brain
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location of heterotopic GM
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anywhere between ependymal surface and subcortical WM
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appearance of heterotopic GM
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nodular or band like matter that follows GM appearance
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presentation of heterotopic GM
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usually p/w sz, developmental delay
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dandy walker malformation
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lrg posterior fossa with high tentorial insertion --> cystically dilated 4th vent that exerts mass effect.
NO cbl vermis or cbl hemisphere. |
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findings assoc w dandy walker malformation
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hydrocephalus
callosal agenesis |
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ddx dandy walker malformation
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dandy walker variant (nml sized posterior fossa, hypoplasia/absence of cbl vermis and hemispheres, without mass effect; torcula in nml position)
mega cisterna magna (torcula in nml position. nml sized post fossa and nml vermis/cbl hemispheres, no mass effect) arachnoid cyst |
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spinal lesions associated with NF1
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neurofibromas
meningocele scoli |
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pathophys of heterotopic grey matter
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as neurons migrate from germinal matrix to overlying cerebral cortex, journey can be interrupted --> trapped nests of GM deep within the brain
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osseous lesions assoc with NF1
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pseudoarthrosis
rib abn ("ribbon abn") |
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location of heterotopic GM
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anywhere between ependymal surface and subcortical WM
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classic features of NF2
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b/l accoustic neuromas
meningiomas other schwannomas (esp CN5 involvement) |
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appearance of heterotopic GM
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nodular or band like matter that follows GM appearance
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presentation of heterotopic GM
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usually p/w sz, developmental delay
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dandy walker malformation
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lrg posterior fossa with high tentorial insertion --> cystically dilated 4th vent that exerts mass effect.
NO cbl vermis or cbl hemisphere. |
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findings assoc w dandy walker malformation
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hydrocephalus
callosal agenesis |
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ddx dandy walker malformation
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dandy walker variant (nml sized posterior fossa, hypoplasia/absence of cbl vermis and hemispheres, without mass effect; torcula in nml position)
mega cisterna magna (torcula in nml position. nml sized post fossa and nml vermis/cbl hemispheres, no mass effect) |
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spinal lesions associated with NF1
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neurofibromas
meningocele scoli |
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osseous lesions assoc with NF1
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pseudoarthrosis
rib abn |
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classic features of NF2
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b/l accoustic neuromas
meningiomas other schwannomas (esp CN5 involvement) |
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spinal manifestations of NF2
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meningiomas
ependymomas schwannomas neurofibromas |
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skin lesions of TS
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adenoma sebaceum
ash-leaf spots |
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brain lesions of TS
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subependymal hamartomas
cortical tubers SEGA |
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where are SEGAs found
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near foramen of Monro (can exhibit mass effect and invade parenchyma)
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appearance of subependymal hamartomas
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parallel WM signal, can calcify (once Ca, then iso/high T1)
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Mnemonic for ring enhancing lesions in brain
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Meningioma
Abscess GBM Infarct (subacute) Contusion Demyelinating dz Resolving hemorrhage, radiation necrosis |
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mnemonic for glial tumors that can calcify
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"Old elephants age gracefully" - in decreaseing order of frq of calcs
Oligo Ependymoma Astrocytoma GBM |
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Gliomatosis cerebri
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infiltratation of astrocytes in varying degrees of differentiation - 3 lobes must be involved
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supratentorial abn associated w chiari II
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hydrocephalus
partial/complete agenesis of CC enlarged massa intermedia dysplastic posterior cingulate gyrus |
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findings in brain in NF1
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non-neoplastic lesions in WM and GP
optic gliomas high signal in GP on T1 and T2 |
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involvement of optic pathway in NF1
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fusiform enlargement of optic nerve +/- enhancement
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what is benign myelin vacuolization associated with
complication |
NF1
can degenerate into a glioma |
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vasc lesions assoc with NF1
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aneurysm
vascular ectasia stenosis moyamoya |
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what class of intra-axial tumors is most common in brain
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glial (astrocytomas)
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how do gliomas spread
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spread through WM tracts (corona radiata, corticospinal, etc), natural passages, subpial and subependymal surfaces, through meninges
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which primary brain neoplasms have high N:C ratio
how does this affect imaging characteristics |
LMNoP
lymphoma Medulloblastoma Nb pineoblastoma they are hyperdense on CT low on T2 b/c decreased free water |
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which mets have a high N:C ratio
how does this affect imaging characteristics |
adeno of breast, lung, colon
melanoma they are hyperdense on CT low on T2 b/c decreased free water |
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most common locations of pilocytic astrocytoma
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cbl >>>> optic pathways, hypothalamus
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what syndrome is pilocytic astroctyoma associated with
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NF1
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appearance of pilocytic astrocytoma
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66% are cyst like with enh mural nodule
33% solid mass +/- necrotic central calcs |
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ddx of a cystic cbl mass with enhancing mural nodule
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pilocytic astrocytoma (0-9 yo)
hemangioblastoma (35yo) |
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which tumor is #1 primary cbl tumor in posterior fossa in adults
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hemangioblastoma
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what cells do ependymomas originate from
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ependymal cells that line the ventricles and central canal of spinal cord
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most common location of ependymoma
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4th vent most common (esp in kids)
ventricles spinal cord if tumor is supratentorial, then it is often intra-axial |
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CT appearance of ependymoma
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iso with calcs, cystic change, poss hemorrhage
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Mr appearance of ependymoma
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low on T1, high on T2
hetero enhancement |
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DDx ependymoma (not w/i posterior fossa)
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choroid plexus papilloma
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most common type of CNS lymphoma
who gets it |
B Cell, non-Hodgkins
immunosupp. pts (HIV) |
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CT/MR appearance of primary CNS lymphoma
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hyperdense on CT
high on T1, low on T2 (high NC ratio) |
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location of priomary CNS lymphoma
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adj to ventricles, along leptomeninges
most are supratent 10% in cbl |
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which malig can --> butterfly glioma
pathophys behind appearance |
GBM
lymphoma spread of tumor via CC to b/l frontal lobes; will see abn signal in CC |
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who gets SPNET
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children ~5yo, males > females
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what does SPNET stand for
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Supratentorial primitive Neuroectodermal tumor
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appearance of SPNET
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lrg hetero mass with soli/cystic components deep in cerebral WM
+calcs, necrosis, and hemorrhage +enhances |
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MR signal of SPNET
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low on T1 and T2
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location of SPNET
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cerebral WM
or perivent/intravent location with hydroceph |
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ddx mega cisterna magna
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retrocerebellar arachnoid cyst
epidermoid neoplasm DW malform DW variant |
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types of migrational abnormalities
which is most severe (*) |
lissencephaly*
pachygyria polymicrogyria |
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etiology of migrational abn
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arrested neuronal migration
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appearance of lissencephaly
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no gyri
brain has hourglass appearance abn thick cortex, with 4 cortical layers present |
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appearance of pachygyria
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incomplete lissencephaly
broad thickened gyri with shallow sulci |
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appearance of polymicrogyria
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cortical dysplasia, with thick mantle of GM with multiple small gyri
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clue to suggest chroroid plexus papilloma
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in kids, you don't have calcs within choroid plexus
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CT appearance of chroroid plexus papilloma
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well defined mass, iso/hyperdense, multilobulated
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MR appearance of chroroid plexus papilloma
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iso T1, high T2
marked enhancement |
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where does central neurocytoma arise
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septum pellucidum or ventricular wall.
50% arise from foramen of monro 10% b/l |
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who gets central neurocytoma
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20-40yo
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Ct/MR appearance of central neurocytoma
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hyperdense on CT
high on T1 and T2 has a swiss cheese appearance 2/2 multiple cysts. intense enhancement |
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what does SEGA stand for
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subependymal giant cell astrocytoma
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what is SEGA assoc with
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TS
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classic findings of SEGA
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any mass within foramen of monro
also, look for cortical or subependymal hamartoma |
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location & appearance of colloid cyst
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anterior to 3rd ventricle
hyperdense on CT can be cystic or heterogeneous T1 and T2 variable, no intense enhancement |
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cells that comprise colloid cyst
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resp epithelium
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neoplasms in pineal region
(*) for malignant |
pineal cyst
*pineoblastoma *pineocytoma germ cell tumor |
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Most common post fossa tumors in kids
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Glioma (brainstem)
Astrocytoma (pilocytic) Medulloblastoma Ependymoma |
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#1 cbl tumor in adults
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hemangioblastoma
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who gets medulloblastoma
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kids 4-8yo
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location of medulloblastoma
why |
in kids, cbl vermis, in adults it's in hemisphere
arises from undifferentiated bipotential cells that start midline and migrate laterally |
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appearance of medullo on CT/MR
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hyperdense, +/- cystic changes, necrosis and calcs
MR: low on T1, var on T2; blurred cbl folia, intense hetero enhancement |
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how to differentiate astrocytoma from medulloblastoma on cCT
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on CT, astrocytoma is low density, medullo is high
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neurocutaneous abn associ with sturge weber
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port wine nevus (in CNV distrib)
pial angiomatosis |
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appearance of pial angiomatosis
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gyriform calcifications, atrophy and gliosis
also, nml venous drainage is altered, so --> enlargement of deep and subependymal veins |
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What does the superior sagittal sinus become as its draining
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right transverse sinus, right sigmoid sinus and right IJ
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What does the straight sinus become as its draining
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left transverse sinus
left sigmoid sinus left IJ |
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Branches of the ICA
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1. Cervical ICA
2. Petrous (vertical, genu, and horizontal portions) 3. Lacerum 4. Cavernous (post/ant genu) 5. Clinoid 6. Ophthalmic 7. Communicating |
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Contents of meckel's cave
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CN V3
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what is Meckel's cave
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CSF filled extension of the prepontine cistern, enclosed by dura
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what do the cisterns communicate with and how
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communicate with each other; also communicate with ventricles via foramen of magendie and luschka
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pathophysiology of CC fistula
types |
AV shunt between ICA (+/- ECA) and cavernous sinus
direct: high flow with single hole fistula btwn ICA/CS indirect: dural AVF suppled by many ECA and cavernous ICA branches. |
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how does CC fistula often present clinically
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painful opthalmoplegia
CN 3,4, or 6 palsy; exophthalmos, intra/periorbital edema |
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key findings to dx CCF
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dilated superior ophthalmic vein, intra/peri-orbital edema
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ddx for CCF
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thyroid ophthalmopathy
orbital pseudotumor Talosa-Hunt syndrome cav sinus thrombosis |
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what is talosa-hunt syndrome
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p/w painful opthalmoplegia
Sup orbital vein is not enlarged no tinnitus or bruit (unlike CCF) |
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DDx for suprasellar tumor/masses
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SATCHMO
Sella (pituaitary) tumor, sarcoid Aneurysm, arachnoid cyst Teratoma Craniopharyngioma Hypothalamic glioma, hamartoma of tuber cinereum, histiocytosis Meningioma Optic nerve glioma |
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DDx for CPA masses
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AMEN
Acoustic schwannoma Meningioma Ependymoma Neuroepithelial cysts (arachnoid, dermoid) |
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Findings of craniopharyngioma
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Suprasellar mass +/- intracellar extension
Calcs are seen peripherally Variable T1, high T2, +enhances |
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DDx craniopharyngioma
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pituitary ademona wiht suprasellar extension
Thrombosed aneurysm (usually calcs are more eccentric and assoc with vascular flow voids) |
