Neoplasms Flashcards
What areas of the brain are most common for brain tumors in adults and in children?
Adults: supratentorial
Children: infratentorial
Recap from stroke lectures: which kind of stroke has a more rapid increase in intracranial pressure?
Hemorrhagic stroke –bleeding induces a fast rise in ICP, whereas inflammation in an ischemic stroke develops over a couple days.
What are symptoms of increase in ICP?
Headache
Nausea and vomiting
Lethargy
“Gliomas” includes malignancies from which cells?
Astrocytoma
Ependymoma
Oligodendroglioma
While tumors arise from errant stem cells, they tend to recapitulate ____________.
certain lineages (such as astrocytes, ependymal cells, etc.)
What is the only glioma that has a grade I designation?
Astrocytoma (called pilocytic astrocytoma)
“Anaplastic gliomas,” regardless of the lineage type, are always grade _________.
III
Glioblastomas are always grade _____.
IV
The most common subtype of glioma seen in children is __________.
pilocytic astrocytoma
What age group are posterior fossa neoplasms more commonly seen in?
Children
Describe the histologic appearance of pilocytic astrocytoma.
Long, bipolar cells with hairlike processes
Rosenthal fibers (pink, corkscrew fibers)
Stains for GFAP (glial fibrillary acidic protein)
BRAF:________ is a common fusion for pilocytic astrocytoma.
KIAA; this protein’s function is not known, but when fused with BRAF it constitutively activates it
Describe the gross appearance of pilocytic astrocytomas.
Cystic
Well-demarcated
What feature makes a diffuse astrocytoma an anaplastic astrocytoma?
Increased mitoses
Diffuse astrocytomas appear in a “___________ array.”
patternless (“like someone threw Cheerios all over the floor”)
Describe the gross appearance (and clinical implication thereof) of diffuse astrocytomas.
Poor-demarcation
This makes them not amenable to surgical resection.
Anaplastic oligodendrogliomas usually have markedly elevated _________.
MIB-1
What genetic marker is unique to oligodendrogliomas?
1p19q co-deletions
Gangliogliomas are ______-growing and as such grade _____.
slow; I
Gangliogliomas are a common source of _________.
temporal-lobe seizures (these neoplasms almost always develop in the temporal lobes)
Medulloblastoma is, by definition, a tumor of the ___________.
cerebellum
Medulloblastomas are more common in what demographic?
males; children under 16
Children younger than what age cannot be given radiation therapy?
One year
What is the only brain tumor that is staged?
Medulloblastoma
What chromosome is commonly affected in medulloblastoma?
17
“Rosettes” are histologically found in what CNS tumors?
Medulloblastoma and ependymoma
How do cerebellar external granule cells migrate?
Inward along the gradient of sonic hedgehog
What kind of herniation does doing an LP on a person with increased ICP cause?
Tonsillar
What demographic has the highest rate of meningioma?
Females, 50 - 59 (MENingiomas at MENopause)
What cranial nerves have Schwann cells?
3 - 12
True or false: the neoplasm with long, hairlike cells that have Rosenthal fibers has a strong tendency to dedifferentiate and upgrade.
False. This tumor (the pilocytic astrocytoma) is grade I and usually remains so
What cancer usually presents in the 4th ventricle in adults and the lateral ventricles in children?
Choroid plexus papilloma
Two CNS neoplasms almost always possess IDH1 mutations: _____________.
astrocytomas and oligodendrogliomas
What is an astrocytoma without IDH1/2 mutations?
Glioblastoma
_____________ often presents with a “chicken wire” pattern.
Oligodendroglioma
Today, diagnosis of oligodendroglioma requires ______________.
detection of LOH 1p, 19q
Which grades of gliomas demonstrate necrosis?
Only grade IV (by definition)
True or false: LOH 1p, 19q predicts better outcomes.
True
The most common glioma is ____________.
glioblastoma multiforme (unfortunately)
How do most glioblastoma multiforme tumors arise?
De novo (i.e., they do not evolve out of lower grade tumors)
Of the 180,000 CNS malignancies per year, how many are primary?
1/6
What genetic signature do diffuse astrocytomas have?
IDH mutations and loss of 17p
Loss of PTEN and amplification of EGFRvIII often causes ___________.
glioblastoma multiforme
Isocitrate dehydrogenase usually produces __________; the mutants, however, produce ____________.
alpha-ketoglutarate; 2-hydroxyglutarate
Medulloblastomas are thought to develop from __________ cells.
external granule layer
