CNS Tumors Flashcards
MC brain tumors
mets from distant neoplasms
difference in location of brain tumors between adults and children
adults - supratentorial
children - infratentorial
ionizing radiation in therapeutic doses has been assoc. with which brain tumors?
meningiomas
astrocytomas
sarcomas
most common sx. of brain tumor
headaches
seizures (focal or generalized)
mental status changes - memory loss, lack of concentration, changes in personality, apathy
clinical presentation of brain tumor in children
decreased appetite and weight loss reduced school performance dizziness ataxia (gait) neck pain bulbar weakness
what can a ring-enhancing lesion on MRI mean?
mass lesion –> disruption of BBB by infiltrating neoplasm
BUT can also be seen in infections, subacute infarction, abscess, MS plaque, AVM, radiation necrosis
what test can be used to detect changes in brain tissue that are assoc. with the type and grade of tumor?
MR spectroscopy
- looks at peak of N-acetyl aspartate assoc. with neuronal loss
what are the 4 gliomas
astrocytoma
oligodendroglioma
ependymoma
choroid plexus papilloma
MC tumor in adults between 40-60 years old
glioblastoma multiforme (grade IV astrocytoma)
pathology seen in glioblastoma multiforme
highly malignant tumors with anaplasia, high cellularity, round/pleomorphic cells, nuclear atypia, vascular proliferation and necrosis
how do you differentiate between grade III and grade IV astrocytoma
grade IV has neovascularization and necrosis; they can also be mutlfocal and infiltrate brain widely
grade IV astrocytoma (GBM) on neuroimaging
solitary brain lesion (in deep white matter, BG or thalamus) with contrast enhancement, surrounding edema –> butterfly pattern
tx. regiment for GBM
surgical resection
radiation w/ concurrent temozolomide (cytotoxic alkylating agent) - continue this for 6 months
- consider nitrosurea drugs for combination therapy
how do you tx local recurrences of GBM
stereotactic radiosurgery and hmAb bevacizumab (sequesters VEGF)
what are the origins of low grade astrocytomas (I and II)
astrocytes (glial cells)
ependymal cells
in children, where do low grade astrocytomas occur
cerebellum
typical presentation of slow growing tumors
seizures
study of choice to dx glioma
MRI with contrast
- most lesions are bright on T2 and FLAIR
tx. for low grade gliomas (Astrocytoma I and II)
close observation with serial neuroimaging
surgery if total resection is possible
consider radiation/chemo
genetic signature of oligodendroglioma
codeletion of Xm arms 1p and 19q
common location of oligodendroglioma
frontal lobes, basal ganglia, thalamus
- usually have very SLOW growth
pathology features of oligodendroglioma
calcification
- perinuclear halos with swollen cytoplasm under microscopic
oligodendroglioma on neuroimaging
low intensity on T1, high intensity on T2
vasogenic edema uncommon
contrast enhancement = poor prognostic sign
tx of oligodendroglioma
total resection if possible
local radiation
PCV chemotherapy
PCV chemotherapy
procarbazine
lomustine
vincristine
- temozolomide used increasingly
which tumor arises in spinal canal as intramedullary tumor in adults?
ependymoma
in children, where are ependymomas located
intracranially in 4th ventricle
histological hallmark of ependymomas
perivascular pseudorosettes - halo of cells surrounding central vascular lumen
tx of ependymoma
surgery to decrease tumor burden followed by radiation and chemotherapy; recurrence rates are high so close follow up with MRI
origin of meningioma
meningothelial (mesodermal) cells of dura mater
common locations of meningioma
cerebral convexities, falx cerebri and sphenoid wing
histology of meningioma
sheets of plump, uniform meningothelial cells with tendency to form whorls; P4 receptors found
meningioma on MRI
isointense on T1 and T2 with intense contrast enhancement
calcifications seen on CT scan
hyperostosis
osteoblastic reaction seen in CT/plain Xrays may indicate meningioma invasion of bone
tx of meningioma
surgical removal (preceded with endovascular embolization)
origin of medulloblastoma
primarily at medullary velum of 4th ventricle; primitive neuroectodermal tumor
presentation of medulloblastoma
rapidly growing tumor that infiltrates surrounding tissue and extends toward 4th ventricle producing hydrocephalus and may spread via CSF intracranially and to spinal cord
medulloblastoma on MRI
heterogenous contrast enhancing midline tumor compressing the 4th ventricle
tx medulloblastoma
surgery plus radiation and chemo, steroids for vasogenic edema
prognosis of medulloblastoma
poor prognosis in children with mets or subtotal resection; good prognosis with radical resection and radiation dose above 50 Gy to entire neuraxis
acoustic schwannomas are MC among…
women
common location of schwannomas
vestibular CN VIII in cerebellopontine angle, involving the facial and trigeminal nerves
histology of schwannoma
sheets of uniform spindle cells, forming palisades called Verocay bodies
tx of acoustic schwannoma
if sx, stereotactic radiosurgery (gamma knife) esp. if does not compress brain stem or is < 3 cm
ganglioglioma
seen in children and young adults, mixture of neurons and glial cells
–> usually in cerebral hemisphere with slow growth and long duration of sx
ganglioglioma on MRI
increased T2 signal with characteristic swollen gyri
tx of ganglioglioma
surgery
Tx of choice for Primary CNS lymphoma
high dose systemic MTX-based chemotherapy (along with cytarabine, temozolomide, rituximab) w/ wo radiation
- dramatic response to steroids, but tumor recurs within months
MC distant neoplasms with mets to brain
lung skin - melanoma kidney - renal cell ca breast colon
where are mets usually localized to
gray-white junction and tend to be solitary but multiple are not unusual
tx of brain mets
single lesions - resected followed by radiation
drop metastases
intradural extramedullary spinal mets that arise from intracranial lesions (MCC is ependymomas or medulloblastomas)
what test should be avoided with medulloblastoma
LP - unless CT shows no obstructive lesion to prevent cerebellar tonsillar herniation
Nf2 associated tumors
bilateral vestibular schwannoma
meningiomas
intramedullary ependymomas
brain mets that bleed easily
melanoma
renal cell carcinoma
choriocarcinoma
low dose radiation therapy is assoc. with what brain tumors
meningiomas
gliomas
children who receive radiation for primary tumors are at increased risk of?
secondary intracranial gliomas and sarcomas
what two things increase risk of CNS lymphoma
HIV
post-transplant immunosuppression
diagnostic test of choice for brain tumor evaluation
MRI with contrast
most effective tx for malignant gliomas
radiation
typical imaging characteristics of brain mets
smaller, multiple at grey-white junction at distal capillaries and assoc. with significant edema
