Brain Tumors Flashcards
brain tumor complications
hemorrhage, hydrocephalus, herniation
hemorrhagic mets
melanoma, RCC, thyroid, choriocarcinoma
extra-axial mass findings
CSF cleft, buckling of gray matter, gray matter interposed between mass and white
T2 hypointense tumors
mets containing dessicated mucin, hypercellular tumors
T1 hyperintense tumors
melanoma, dermoid/teratoma, hemorrhagic mets
glial cells differentiate into?
astrocytes, oligodendrocytes, ependymal cells, choroid plexus cells
astrocyte function
biochemical support to endothelial cells to maintain BBB
oligodendrocyte function
maintain myelin around CNS axons
peripheral counterpart to oligodendrocytes
Schwann cell
ependymal cell function
circulate CSF with mutlipple cilia, line ventricles/central canal of spinal cord
choroid plexus cells
produce CSF; modified ependymal cells
line body/temporal horn of lateral ventricles, roof of 3rd/5th ventricle
grade I astrocytoma: JPA
juvenile pilocytic astrocytoma
seen in posterior fossa of children
well circumscribed cystic mass with enhancing nodule, little edema; may compress 4th ventricle
can also occur in optic pathway
JPA association
NF1 if it is in the optic pathway
posterior fossa JPA is not associated with NF1
fibrillary astrocytomas
low grade astrocytoma, anaplastic astrocytoma, GBM
low-grade astrocytoma: WHO type, imaging appearance
WHO grade II
T2 hyperintense mass, no enhancement; subtle
anaplastic astrocytoma: WHO type, imaging appearance
WHO grade III
thickened cortex, irreguarly enhancing mass that may appear identical to glioblastoma –> eveutaly progresses to glioblastoma
GMB: WHO type, patient population, imaging appearance
WHO IV
older adults, most common CNs malignancy
variable appearance (multiforme) but typically white matter mass with heterogenous enhancement and T2 nonenhancing prolongation
crosses midline via corpus callosum (butterfly glioma)
ddx for transcallosal mass
GBM, lymphoma, demyelinating dx
glioblastoma cerebri: WHO type, imaging
WHO II/III
affects at least 2 lobes plus extra-cortical involvement
diffuse T2
mass effect, but no enhancement
oligodendroma: WHO type, pt, imaging
WHO II
young/middle aged pt with seizures
slow growing cortical based mass; tend to calcify
variants: oligoastrocytoma, anaplastic oligodendroglioma
ependymoma: imaging, pts
typically posterior fossa kids, spinal cord older adults
pediatrics: toothpaste tumor, fills 4th ventricle (ddx is medulloblastoma)
adult: intramedullary spinal cord (ddx astrocytoma)
lhermitte duclos
WHO I; dysplastic cerebellar gangliocytoma (hamartoma/neoplasm)
corduroy/tiger striped cerebellar hemisphere; enhancement rare
Lhermitte duclos association
Cowden syndrome; multiple hamartomas, increased risk of cancer
PNET tumors
WHO IV, aggressive childhood embryonal tumors
ATRT, medulloblastoma
usually located in posterior fossa
atypical teratoid/rhabdoid tumor (ATRT)
WHO IV, aggressive tumor
occurs in younger patients, usually in posterior fossa
associations for ATRT
malignant rhabdoid tumor of kidney
medulloblastoma
WHO IV; PNET, small blue cell tumor
most common pediatric brain tumor
midline cerebellar vermis
hyperattenuating on CT
hypointense on T2, low ADC
internal hemorrhage/calcifications
sugar coating (Zuckerguss)
leptomeningeal mets, common in medulloblastoma
imaging should be performed on brain and spine
medulloblastoma in young adult
eccentric in posterior fossa
Ddx for tumors with cyst and enhancing nodule
JPA, hemangioblastoma, PXA, ganglioglioma
also neurocysterosarcosis, parasites/abscess
hemangioblastoma
WHO I
vascular tumor, cystic mass with enhancing mural nodule
typically cerebellum, medulla, spinal cord, so
associated with syrinx wiht spinal cord
hemangioblastoma association
VHL
pleomorphic xanthroastrocytoma
WHO II astrocytoma variant
kids and adolescents, usually with chronic epilepsy
supratentorial cortical cystic mass with enhancing mural nodule ; thickened dura
PXA vs ganglioglioma
PXA causes dural thickening, ganglioglioma does not
ganglioglioma
adolescent/young adult tumor with medically refractory temporal lobe epilepsy
neuroglial tumor
temporal lobe cyst and enhancing nodule, that calcifies; may cause calvairal remodeling and scalloping
intraventricular tumors
central neurocytoma, choroid plexus papilloma, intraventricular meningioma, subependymal giant cell astrocytoma, subependymoma,
intraventricular meningioma
solid mass in trigone of lateral ventricle
hypercellular, homogenously enhancing
typically older patients
subependymal giant cell astrocytoma
WHO I
enhancing mass near foramen of monroe
SEGA associations
tuberous sclerosis: subependymal nodules and hamartomas also seen
subependymoma
nonenhancing low grade tumor from subependymal astrocytes/ependymal cells/precursor cells?
middle age/older adults
obex of 4th ventricle or foramen of monro
CNS lymphoma
usually diffuse large B cell lymphoma
primary CNS lymphoma is usually periventricular ( and melts away with chemoradiaiton but can recur aggressively
appearance depends on immune status
CNS lymphoma vs toxoplasmosis clinical/imaging options
- empiric anti-toxoplasmosis therapy
- thallium scanning (CNS is thallium avid)
- PET: toxo doesn’t have uptake
- perfusion scanning: CNS has increased relative cerebral blood volume
most common intra-axial mets, location
lung, breast, melanoma
commonly at the gray-white junction
dural neoplasms
meningioma, dural mets
most common extra-axial tumor
meningioma
meningioma cell of origin, pt population
meningoepithelial cells or arachnoid “cap” cells
elderly adults with female predominance and most often asymptomatic`
most common pediatric brain tumor
medulloblastoma
most common cystic mass with enhancing mural nodule in posterior fossa in kid?
JPA
intraventricular mass that pushes through 4th ventricle
ependymoma
cystic mass with enhancing mural nodule and flow voids? history of VHL?
hemangioblastoma
pt younger than age of medulloblastoma? renal mass present?
ATRT
posterior fossa mass in adult with little/no enhancement
astrocytoma
posterior fossa mass in young adult, lateral location?
medulloblastoma
important landmarks of CP angle
pons, cerebellum, posterior aspect of petrous temporal bone
CN 5, 7, 8 and AICA
schwannoma
vestibulocochlear (CN 8) nerve schwannoma is the most common CPA mass
imaging appearance of schwannoma
T2 hyperintense, “ice crea cone” appearance protrouding through porus acousticus, may become cystic when larger
second most common CPA mass
meningioma
features of CPA meningioma
shorter dural enhancement, bony hyperostosis, calcifications
does not enlarge porous acousticus, unlike schwannoma
arachnoid cyst
benign CSF filled lesion, usually congenital
usually supratentorial but may be in CPA
follows CSF on all sequences, does not restrict diffusion (unlike epidermoid cyst)
CPA aneurysm
vertebrobasilar aneurysm; avidly enhances
look for flow void or pulation artifacts
CPA epidermoid
arises from ectopic ectodermal epithelial tissue
cauliflower like surface as it grows and encases adjacent structures
restricts diffusion, similar to T1 and T2 cyst; does not suppress on FLAIR
intraaxial CPA masses
posterior fossa mass may invade laterally into CPA, exophiytic brainstem glioma or met
lateral medulloblastoma in older children/young adults
ependymoma may squeeze into lateral 4th ventricle
hemangioblastoma
VHL in the brain
hemangioblastoma, endolymphatic sac tumor (posterior petrous ridge)
rathke’s pouch
invagination from primitive oral cavity
issues with rathke’s pouch
rathke’s pouch cyst or craniopharyngioma
anterior lobe of pituitary gland
growth hormone, ACTH, prolactin, TSH, FSH, LH
posterior lobe of pituitary gland
neuroectoderm, vasopressin/oxytocin
pituitary gland signal
hyperintense on T1; posterior pituitary bright spot
empty sella
normal variant although may be seen with pseudotumor cerebri
ddx for intrinsic pituitary mass
pituitary adenoma, rathke’s cleft cyst, hypophysitis; craniopharyngioma
pituitary microadenoma
<1 cm in size; symptoms of hormone excess; usually hypoenhancing
pituitary macroadenoma
> 1 cm, mass effect (compression of optic chiasm), bony sella remodeling, may encase carotid and do not narrow it (unlike meningiomas or mets); may bleed after medical treatment
lymphocytic hypophysitis
autoimmune inflammatory disroder in peripartum women
presentation: diabetes insipidus, headache, visual impairment, endocrine dysfunction
MRI: thickening/intense enhancement of pituitary stalk
granulomatous hypophysitis
inflammation of pituitary/infundibulum, may be secondary to sarcoid, wegener, TB, LCH
LCH hypophysitis
disease of children; imaging identical to lymphocytic hypophysitis
rathke cleft cyst
extrinsic to pituitary
suprasellar mass mnemonic
SATCHMO
Sarcoidosis/Suprasellar extension of an adenoma.
Aneurysm.
Teratoma (dermoid cyst)/Tolosa hunt.
Craniopharyngioma/Cleft cyst (Rathke’s).
Hypothalamic glioma (adults)/Hypothalamic hamartoma (children). Meningioma/Metastasis.
Optic nerve glioma.
craniopharyngioma
most common suprasellar lesion of childhood; squamous epithelial remnants of rathke’s pouch that produce keratin
craniopharyngioma age distribution, locaiton
bimodal: childhood, late middle age
sella/suprasellar regions
imaging appearance craniopharyngioma
enamel production > calcification with intracystic machine oil composed of desquamated squamous epithelium, keratin, cholesterol
complex cystic mass, T1 bright
avid enhancement of solid elements/cyst walls
calcifications; usually separate from pituitary
rathke’s cleft cyst component
simple columnar/cuboidal epithelium; precursor of anterior lobe of pituitary gland
middle aged adults
rathke’s cleft imaging appearance
cyst content: iso to CSF or T1 hyperintense
claw sign of enhancing pituitary tissue wrapping around cyst
does not calcify
suprasellar meningioma
common with females, visual loss due to optic pathway involvement
astrocytoma (optic pathway glioma)
second most common suprasellar mass in children
associated with NF1
germinoma
most common intracranial germ cell tumor
epidermoid/dermoid cyst
benign inclusion cyst
CPA middle aged adults for epidermoids; follows CSF signal and restricts diffusion
posterior fossa adult males for dermoids; contain fat which can cause meningitis with rupture
aneurysm
saccular supraclinoid ICA aneurysm
pulsation artifact present on MRI
hamartomata of tuber cinereum
hypothalamic hamartoma
ectopic hypothalamic neural tissue with precocious puberty and gelastic seizures (laughing spells)
does not enhance
suprasellar pediatric masses
craniopharyngioma, optic pathway glioma, germ cell tumor, hypothalamic hamartoma, LCH
suprasellar mass in adults
pituitary macroadenoma, meningioma, craniopharyngioma, rathke’s cleft cyst, aneurysm, lymphocytic/granulomatous hypophysitis
pineal gland location
posterior aspect of 3rd ventricle; between thalami
located between cerebral veins and vein of galen
pineal gland production
melatonin; does not have BBB
complications of mass in pineal region
compress midbrain, compress cerebral aqueduct, compression of tectal plate (Perinaud syndrome–inability to look up, pupillary light dissociation, nystagmus)
importance of cerebral veins an pineal region masses
tentorial meningiomas depress internal cerebral veins
pineal gland masses lift cerebral veins
extragonadal germ cell tumros (brain)
midline
germinoma and teratoma germ cell tumors are the most and second most common pineal region tumors
germinoma – pineal
age, imaging appearance, treatment
most common pineal region tumor in young people (10-1 yo)
germinoma will engulf pineal gland and be centrally calcified
image for leptomeningeal deposits
treatment with radiotherapy
teratoma – pineal
second most common pineal region tumor
worse prognosis compared to germnoma
heterogenous imaging (intralesional fat); prone to hemorrhage and coarse calcifications
pineal cysts
more common in women; seen commonly on MRI
usually <1 cm and asymptomatic
may have some peripheral enhancement, rim calcification, or be slightly complex
pineocystoma
cystic lesion with peripheral enhancement
pineocytoma
low grade WHO I/II slow growing pinealocyte tumor
solid component would enhance
pineoblastoma
malignant grade WHO IV tumor of children, same as PNET (medulloblastoma)
trilateral retinoblastoma (when there is bilateral retinoblastoma + pineal gland)
quadrilateral retinoblastoma if sella also inolved
pineoblastoma complications, imaging findings
obstructive hydrocephalous
restricts diffusion, periherally calcifies like an exploded calcification (vs englulfing like germinoma)
pineal metastases
lack BBB, easy site of mets
leptomeningeal disease usually has pineal mets
pineal region masses
glioma, vein of galen aneurysm, meningioma, quadrigeminal plate lipoma,
