Ch 28-CNS (tumors) Flashcards
This is the most common group of primary brain tumors and includes astrocytomas, oligodendrogliomas, and ependymomas
Gliomas
___ account for about 80% of adult primary brain tumors and are usually found in the cerebral hemispheres. Pts present with seizures, headaches, and focal neurologic deficits related to anatomic site of involvement
Infiltrating astrocytomas
Which age group is most likely to develop an infiltrating astrocytoma?
Adults
The majority of primary glioblastomas (classic subtype) have mutations of ___ gene, deletions of Chromosome ___, and amplification of ___ oncogene
PTEN
Chr 10
EGFR
The proneural type is associated with secondary glioblastoma and characterized by mutations of ___, and point mutations in the ___ genes
TP53
IDH1 and IDH2
Among the higher grade astrocytomas (III and IV), presence of the mutant form of ___ is associated with a significantly better outcome than in tumors with the wild-type form
IDH1
___ has a similar histologic appearance to anaplastic astrocytoma but has necrosis and vascular/endothelial cell proliferation. The necrosis occurs in a serpentine pattern and has pseudo-pallisading tumor cells in necrotic regions
Glioblastoma
What is the prognosis for pts with glioblastoma?
VERY POOR
What is the grading of a pilocytic astrocytoma, who is more likely to be diagnosed, and where are they usually located?
Grade 1, typically occur in children and young adults, usually located in cerebellum
These inhibitors may play a role in the tx of pilocytic astrocytomas
BRAF
This type of tumor is often cystic with bipolar cells that are GFAP-positive. Rosenthal fibers and eosinophilic granular boides are characteristic findings
Pilocytic astrocytoma
Where do pleomorphic xanthoastrocytomas most often occur, who is most likely to be diagnosed, and what is the grade?
Most often occur in temporal lobe of children and young adults, and is a low grade tumor (II/IV)
This astrocytoma occurs most often in the first 2 decades of life and make up 10-20% of all brain tumors in this age group
Brainstem glioma
This brainstem glioma is the most common, has an aggressive course and short survival
Intrinsic pontine glioma
This brainstem glioma anatomic pattern is often exophytic and a less aggressive course
Cervicomedullary junction
This brainstem glioma anatomic pattern has an even more benin course which may arise in the tectum of the midbrain, pons, or medulla
Dorsally exophytic glioma
This tumor constitues 5-15% of glioma and most common in 4th and 5th decades. Pts may have had several years of neurologic complaints, often including seizures.
Oligodendrogliomas
This glioma presents often with seizures, lesions found mostly in cerebral hemispheres with a predilection for white matter.
Oligodendroglioma
What is the most common genetic alteration (mutation) in oligodendroglioma and how does it affect the prognosis?
IDH1 and IDH1, which occur in up to 90% of oligodendrogliomas and portend a BETTER PROGNOSIS
This co-deletion is seen in up to 80% of cases of oligodendrogliomas and this deletion shows long-lasting responses to chemotherapy and radiation
Co-deletion of Chr 1p and 19q
A fried-egg appearance morphologic pattern is associated with ___
Oligodendroglioma
what is the prognosis of oligodendroglioma?
Better prognosis than those with astrocytomas but those with anaplastic oligodendrogliomas have an overall worse prognosis
What age group is likely to have an ependymoma, where does it normally occur?
First 2 decades of life, typically occur near the 4th ventricle
Constitue 5-10% of primary brain tumors in this age group
This gene is commonly mutated in ependymomas in the SC but not at other sites
NF2 gene on Chr 22
In ependymomas, aberrations of large regions of chromosomes or whole chromosomes tend to have what prognosis?
An overall better prognosis
Perivascular pseudorosettes in which tumor cells are arranged around vessels with an intervening zone and GFAP expression is found in most ___
Ependymomas
___ often manifest with hydrocephalus secondary to progressive obstruction of the 4th ventricle; CSF dissemination is a common occur and portends a poor prognosis
Posterior fossa ependymomas
___ tumors are far less common than glial tumors and most often seen in younger adults and often presents with seizures
Neuronal
___ is the most common of the neuronal tumors of the CNS, has a mix of neuronal and glial cells and presents with seizures. Mostly the temporal lobe
Gangliomas
___ is a malignant embryonal tumor that occurs predominantly in children and exclusively in the cerebellum. It is largely undifferentiated and grade IV
Medulloblastoma
This medulloblastoma subtype tends to occur in older kids, can show monosomy of Chr 6 and nuclear expression of beta-catenin, has the best prognosis
WNT
This medulloblastoma subtype occurs in infants or young adults, has MYCN amplification, intermediate prognosis
SHH
This medulloblastoma subtype has MYC amplification and i17q, occurs in infants and children and has the worst prognosis
Group 3
This medulloblastoma subtype has an i17q alteration without MYC amplification but can have it at times. The prognosis is intermediate
Group 4
This alteration in medulloblastoma subtypes signals a poor prognosis in groups 3 and 4
i17q
In children with medulloblatoma, the tumor is located ___, while in adults it is found ___
Children –> midline of cerebellum
Adults–> lateral locations
Dissemination of this tumor through CSF is a common complication that can lead to drop metastases
Medulloblastoma
What is prognosis for medulloblastoma?
Poor
Grade IV
What is the prognosis of an atypical teratoid/rhabdoid tumor? Who is most likely to get it? Where do they typically occur
Highly malignant
Young children
Posterior fossa and supratentorial compartments in equal proportions
What is the pathologic hallmark of an atypical teratoid/rhabdoid tumor?
Alterations in Chr 22 a hallmark of rhabdoid tumor (hSNF5/INI1)
What is the clinical outcome/prognosis of atypical teratoid/rhabdoid tumorS?
Highly aggressive of the very young, most before age 5 die, within 1 year
This is the most common CNS neoplasm of the immunosuppressed pts
Primary CNS lymphoma
The vast majority of primary brain lymphomas are of __ cell origin
B
In immunosuppressed setting, cells in nearly all primary brain lymphomas are latently infected by ___
EBV
This type of tumor occurs along the midline, most commonly in the pineal and suprasellar regions; accounts for up to 10% of brain tumors in Japanese
Primary brain germ cell tumor
___ is a predominantly benign tumor of adults and prior radiation to head and neck (decades earlier) is a risk factor
Meningioma
The most common cytogenetic abnormality of a meningioma is loss of ___
Chr 22q12 –> NF2 gene –> Merlin
Of sporadic meningiomas, 50-60% harbor mutations in NF2 genes
In meningiomas without NF2 mutations, the most common mutations occur in ___
TRAF7
Higher grade meningiomas are often associated with:
NF2 mutations, loss of CHr 22, and chromosomal instability
This meningioma is highly aggressive with appearance of a high-grade sarcoma
Atypical (malignant) meningiomas
Grade III/IV
Who is more likely to have a meningioma?
Uncommon in children, show moderate (3:2) female predominance, although ratio is 10:1 for spinal meningiomas
Meningiomas often express ___ receptors and may grow more rapidly during ___
Progesterone
Pregnancy
Meningeal carcinomatosis most commonly associated with carcinoma of the ___
Lung and. Breast
List the mutation in the following familial tumor syndromes:
Cowden syndrome: dysplastic gangliocytoma of cerebellum with mutation in ___
Li-Fraumeni syndrom: medulloblastoma caused by mutations in ___
Turcot syndrome: medulloblastoma or glioblastoma with mutations in ___
Gorlin syndrome: medulloblastom with mutation in ____
PTEN
TP53
APC
PTCH
__ is autosomal dominant, 1 in 6000 births, characterized by hamartomas and benign neoplasms involving brain and other tissues
Tuberous sclerosis complex
What are the most frequent clinical manifestations of tuberous sclerosis complex?
Seizures, autism, MR
___ encodes protein hamartin
___ encodes tuberin
TSC1 on Chr 9q34
TSC2 at Chr 16p13.3
__ is autosomal dominant; develop hemangioblastomas of CNS and cysts involving pancreas, liver, and kidneys and have propensity to develop renal cell carcinoma and pheochromocytoma
VHL disease
Hemangioblastomas are most common in ___
Cerebellum and retina
VHL is a tumor suppressor gene on Chr 3p25.3 and encodes the protein VHL and down-regulates ___
HIF-1
Rosenthal fibers are within astrocytic processes and are characteristic of this glial tumor:
Pilocytic astrocytoma
