Neuro: 17.8: CNS Tumors Flashcards
What is a craniopharyngioma?
a tumor that arises from epithelial remnants of Rathke’s pouch
What is the prognosis for medulloblastoma? Why?
- poor
- it grows rapidly and spreads thru the CSF
This is a malignant tumor of oligodendrocytes seen in adults.
oligodendroglioma
What receptor does a meningioma express?
estrogen receptor
What key findings will be seen microscopically in pilocytic astrocytoma?
Rosenthal fibers (astrocytes with thick eosinophilic processes, corkscrew shaped)
What is the most common CNS tumor in children?
pilocytic astrocytoma
What imaging findings will be seen in pilocytic astrocytoma?
- a well-circumscribed, cystic lesion with a mural nodule
- *** “pyloCYSTIC astrocytoma”
What is the tumor that classically arises from astrocytes in a child?
pylocytic astrocytoma
How do pts with schwannomas present?
- tinnitus (ringing in the ears)
- hearing loss
Dx?
- large amounts of necrosis surrounded by pseudopalasading normal tissue
- endothelial cell proliferation
glioblastoma multiforme
Dx?
- a tumor that arises from epithelial remnants of Rathke’s pouch
craniopharyngioma
What is the most abundant glial cell?
astrocytes
What is a glioblastoma multiforme?
- a malignant, high-grade tumor of astrocytes (a glial cell)
- the most common CNS tumor in adults
This is a malignant CNS tumor in children arising from ependymal cells.
ependymoma
How does a meningioma present?
with seizures
Dx?
- a well-circumscribed, cystic lesion with a mural nodule in the cerebellum
pilocytic astrocytoma
What is an ependymoma?
a malignant CNS tumor of ependymal cells seen in children
What is the most common benign CNS tumor in adults?
meningioma
Where does an ependymoma most commonly arise?
in the 4th ventricle
What is a schwannoma?
a benign tumor of schwann cells
How will medulloblastomas appear on microscopy?
- small, round blue cells
- Homer-Wright rosettes
What is the function of the microglia?
phagocytic scavenging in the CNS
Dx?
- whorled spindle cells
- abundant psammoma bodies (laminated calcifications)
meningioma
What is the most common supratentorial tumor?
craniopharyngioma
Dx?
- S100 positive
schwannoma
How does a craniopharyngioma present??
a supratentorial mass in a child or young adult
Who gets medulloblastoma?
children
This is when medulloblastoma spreads into the spinal cord via the CSF.
drop metastases
What are the microscopic findings in craniopharyngioma?
- Cholesterol crystals found in “motor oil”–like fluid within tumor
What microscopic findings are seen in ependymomas?
- perivascular pseudo-rosettes
- Rod-shaped blepharoplasts (basal ciliary bodies) found near the nucleus
This is a malignant CNS tumor of children arising from the neuroectoderm.
medulloblastoma
This is a benign CNS tumor from the arachnoid (meningothelial) cells classically seen in adult females
meningioma
This is:
- the intermediate filament present within glial cells
- marker for glioblastoma multiforme and pilocytic astrocytomas.
GFAP
What are the astrocytes derived from?
neuroectoderm
Dx?
- small, round blue cells
- Homer-Wright rosettes
medulloblastoma
How does an oligodendroglioma present?
seizures
What is the embryonic origin of a craniopharyngioma?
surface ectoderm
What is the tx for glioblastoma multiforme?
Nitrosoureas (Carmustine, lomustine, semustine, streptozocin)
Where does a glioblastoma multiforme most frequently arise?
in the cerebral hemispheres WITH CROSSING OVER the corpus callosum
This is a benign tumor of astrocytes in children.
pilocytic astrocytoma
Where in the brain are oligodendrogliomas usually found?
the frontal lobe
Dx?
- a calcified tumor in the white matter
- “fried egg” appearance
- “chicken wire” capillary pattern
Oligodendroglioma
Dx?
- Rosenthal fibers (astrocytes with thick eosinophilic processes, corkscrew shaped)
pilocytic astrocytoma
What is the tissue that supports the neurons?
glial tissue
What cell forms the BBB?
astrocytes
Dx?
- Cholesterol crystals found in “motor oil”–like fluid within tumor
craniopharyngioma
What is a pylocytic astrocytoma?
a benign tumor of the astrocytes in a child
Dx?
- tumor in the cerebral hemispheres WITH CROSSING OVER the corpus callosum
glioblastoma multiforme
What do pilocytic astrocytomas stain positively for?
GFAP
What is another name for a glioblastoma multiforme?
a butterfly glioma
What kind of cells do meningiomas arise from?
arachnoid
What is a pilocytic astrocytoma?
a benign tumor of astrocytes
Relative to the tentorium, where do CNS tumors in children occur?
children = beneath
On imaging, this will look like a round mass attached to the dura.
meningioma
From what are oligodendrocytes derived from?
neuroectoderm
What is a noncommunicating hydrocephalus?
structural blockage of CSF circulation
Dx?
- a supratentorial mass in a child or young adult
craniopharyngioma
What does an oligodendroglioma look like microscopically?
- a calcified tumor in the white matter
- “fried egg” appearance
- “chicken wire” capillary pattern
What is the most common CNS tumor in adults?
glioblastoma multiforme
What is glial tissue?
the tissue that supports the neurons
How does a craniopharyngioma appear on imaging?
calcified
What is the prognosis for an ependymoma?
poor
What is an oligodendroglioma?
a malignant tumor of oligodendrocytes seen in adults
What is the function of an oligodendrocyte?
myelinate CNS axons
Nitrosoureas (Carmustine, lomustine, semustine, streptozocin) are used to treat _______.
brain tumors, including glioblastoma multiforme
How does an ependymoma present?
hydrocephalus
What is the function of the ependymal cells? Where are they found?
- produce CSF
- lining the ventricular spaces
What is GFAP?
- the intermediate filament present within glial cells
- marker for glioblastoma multiforme and pilocytic astrocytomas
What does a meningioma look like on histology?
- whorled spindle cells
- abundant psammoma bodies (laminated calcifications)
What are Homer-Wright rosettes? What are they assoc. with?
- Circular grouping of dark tumor cells surrounding pale neurofibrils
- seen in medulloblastoma or neuroblastoma
Who gets craniopharyngiomas?
children or young adults
What do schwannomas involve?
- cranial or spinal nerves
- esp. CN8 at the cerebello-pontine angle (CPA)
What is a medulloblastoma?
a malignant CNS tumor of children arising from the neuroectoderm
Medulloblastoma can compress the ____, causing _____.
4th ventricle –> noncommunicating hydrocephalus
What do ependymal cells derive from?
neuroectoderm
Circular grouping of dark tumor cells surrounding pale neurofibrils seen in medulloblastoma or neuroblastoma are called _____.
Homer-Wright rosettes
Where are schwannomas most likely to occur?
- CN8 at the cerebello-pontine angle (CPA)
- “vestibular schwannoma”
Where do pilocytic astrocytoma most often arise?
in the cerebellum (posterior fossa)
Name 2 histological features of glioblastoma multiforme.
- large amounts of necrosis surrounded by pseudopalasading normal tissue
- endothelial cell proliferation
Who most often gets pilocytic astrocytoma?
children
Bilateral schwanommas are seen in _____.
neurofibromatosis type 2 (NF2)
What is the prognosis for glioblastoma multiforme?
death in about 1 year
What is the tumor that classically arises from astrocytes in an adult?
glioblastoma multiforme
The 3 most common mets to the brain come from the ____, _____, and _____.
- lung
- breast
- kidney
What is a meningioma? Who gets them?
- a benign CNS tumor from the arachnoid (meningothelial) cells
- classically seen in adult females
Why do pts with craniopharyngiomas get bitemporal hemianopsia?
compression of the optic chiasm
What are drop metastases? What are they associated with?
when medulloblastoma spreads into the spinal cord via the CSF
If you see bitemporal hemianopsia, think _____ or _____.
- pituitary tumors
- craniopharyngioma
What marker are schwannomas positive for?
S100
Where do meningiomas most commonly occur within the brain?
- near the surfaces
- parasaggital region
Where and how do metastatic lesions to the CNS most often occur?
- at the gray-white junction
- as multiple, well-circumscribed lesions
What is the function of the astrocytes?
- form the BBB
- K+ metabolism
- repair
- NT reuptake
What are the imaging findings in a meningioma?
a round mass attached to the dura
What is the prognosis for craniopharyngioma?
it’s benign but can recur
What are the microglia derived from?
mesoderm (mononuclear origin)
What are meningothelial cells?
cells making up the meninges
Relative to the tentorium, where do CNS tumors in adults occur?
above = adults
Dx?
- perivascular pseudo-rosettes
- Rod-shaped blepharoplasts (basal ciliary bodies) found near the nucleus
ependymoma
What is the marker for the astrocytes?
GFAP
