CNS Tumors

Question 1

Pilocytic Astrocytoma

Answer 1

Most common childhood (sometimes young adults)
Cerebellum, optic pathway, hypothamlus, thalamus, spinal cord, temporal lobe
Demarcated boundaries, easier to resect
Bipolar neoplastic cells
Astrocytoma: BRAF: K1AA fusion

Question 2

BRAF: K1AA

Answer 2

BRAF:MAPK in ras/ raf pathway (almost no mitotic activity)
Plays a role in proliferation, cell survival, differentiation, apoptosis
Understanding these genetics helps us give target rx when surgery is not an option

Question 3

Diffuse Astrocytoma

Answer 3

Adult (30-40)
Grade 2
Cerebral hemisphere (rarely post. Fossa)
Cannot tell where the tumor starts and stops- HARD TO RESECT
Whole brain disease

Question 4

Anaplastic Astrocytoma

Answer 4

dult (45)
Grade 3
Cerebral Hemispheres
IDH1 mutation (+no LOH 1p/19q +p53/ATRX mutation) important in metabolic pathway. When mutated, starts using onco-metbolite

Question 5

Oligodendroglioma

Answer 5

Adult (42)
Grade 2
May show up as calcified
May infiltrate gray matter, may present w/ sz

Question 6

Anaplastic Oligodendroglioma

Answer 6

Adult (48)

WHO Grade 3

Question 7

Glioblastoma

Answer 7

Adult (1o= 62, 2o= 45)
Grade 4
Usually involves cerebellar hemispheres 
Hemorrhagic, granular appearance 
Primary GBM: symptoms less than 4 months

Question 8

Ependymoma

Answer 8

Younger: 0-20
Occurs near ependymal cells most of the time
4th ventricle, presents with hydrocephalus (peds)
Adults get these in the spinal cord

Question 9

Medullobastoma

Answer 9

Most common malignant brain tumor 3-8 yo
Grade 4
~50% survival rate 
Chromo 17 deletion
These can spread through CSF pathways 
Homer wright rosettes 
(Always starts in cerebellum maybe?)

Question 10

Perkingie Cells

Answer 10

class of GABAergic neurons located in the cerebellum. They are named after their discoverer
Sonic hedgehog signal there migration

Question 11

Meningioma

Answer 11

RARE in childhood, women in 50s
Grade 1
Arise from memngies/dura

Question 12

Schwannoma

Answer 12

Slow growing
Rarely maligenet transformation
CN 8 and spinal nerve roots

Question 13

include tumors with low proliferative potential and possibility of cure following surgical resection alone.

Answer 13

Grade I lesions

Question 14

lesions are generally infiltrative in nature, and, despite low level proliferative (ie., mitotic) activity, often recur

progress to a higher grade of malignancy

Answer 14

Grade II lesions

Question 15

Grade II lesions Rx

Answer 15

II tumors may either be treated with watchful waiting (ie., close- interval neuroimaging scans to detect upgrading) or external beam cranial irradiation, depending on location, clinical features, type and size of lesion.

Question 16

tumor is a designation generally reserved for lesions with histological evidence of malignancy, including nuclear atypia and brisk mitotic activity.

Answer 16

Grade III

Question 17

Grade III Rx

Answer 17

In most settings, patients with Grade III tumors receive adjuvant radiation and/or chemotherapy

Question 18

tumor is assigned to cytologically malignant, mitotically active, necrosis-prone neoplasms often associated with rapid pre- and post-operative disease evolution and fatal outcome.

Common examples include glioblastoma and medulloblastoma.

Answer 18

Grade IV neoplasms

Question 19

these tumors appear demarcated from surrounding brain and often contain a cystic component

Answer 19

Pilocytic Astrocytoma

Question 20

the tumor is often cystic and may present with a cyst and mural nodule configuration. It is generally fairly well demarcated and is even more likely to be calcified

Answer 20

Ganglioglioma

WHO Grade 1

Question 21

This tumor is almost always identified in intraventricular locations and can closely mimic the morphological features of normal choroid plexus, except that the fronds or “papillary formations” are more abundant, and the choroid plexus-like cells covering the fronds more crowded and numerous.

Answer 21

choroid plexus papilloma

Question 22

arise in white matter of the cerebral hemisphere predominantly in patients in their 3rd to 5th decade.

boundaries are often impossible to define radiographically, surgically, grossly and microscopically, they can rarely be totally excised.

Answer 22

Diffuse astrocytomas

Question 23

often associated with Rosenthal fibers, an eosinophilic accumulation of intracytoplasmic glial filaments.

Answer 23

Pilocytic Astrocytoma

Question 24

_________, WHO grade II, is characterized by mild hypercellularity compared to normal brain, mild nuclear pleomorphism, irregular distribution of tumor astrocytes, slight variation from one cell to the next in nuclear features and cytoplasmic content and an absence of necrosis, mitotic activity, or microvascular proliferation.

Answer 24

Diffuse astrocytoma

Question 25

originate in cerebral hemispheric white matter, they quickly infiltrate the overlying cortex and present clinically as seizures due to cortical involvement.

Answer 25

oligodendroglioma

Question 26

______________ is composed of cells with round monotonous nuclei that are roughly equally spaced from each other; cells contain little or no visible cytoplasm on H&E and thus manifest a diagnostically-helpful feature of tumor cells with a “fried egg” appearance.

Answer 26

oligodendroglioma

Question 27

Activation of the gene for B-Raf is a common finding in__________

Answer 27

pilocytic astrocytomas

Question 28

This tumor may have mutation in BRAF V600E gene; this allows the possibility of targeted drug therapy in mutated cases.

Answer 28

Ganglioglioma

WHO Grade 1

Question 29

Both tumors possess mutations in IDH1 or less commonly, IDH2

Answer 29

diffuse astrocytomas and oligodendrogliomas

Question 30

This tumor arises from ependymal cells which line the ventricle and most, but not all, are found in intraventricular locations.

Answer 30

ependymomas

Question 31

___________ is diagnosed by histological tissue criteria although usually these tumors lack enhancement or necrosis on preoperative neuroimaging studies.

By definition, it DOES NOT show histological features of necrosis or microvascular proliferation

Answer 31

Anaplastic astrocytoma

Question 32

_____________ is diagnosed by histological tissue criteria although usually these tumors DO show enhancement on preoperative neuroimaging studies

Answer 32

Anaplastic oligodendroglioma

Question 33

___________ are commonly calcified tumors that typically protrude upward from the floor of the 4th ventricle as exophytic masses. When they occur in the spinal cord they are usually fairly well demarcated from cord and total or near total excision may be possible

Answer 33

Ependymomas

Question 34

Often microvascular proliferation is present histologically, which corresponds to the “enhancement” seen on preoperative neuroimaging studies after administration of contrast dye (gadolinium). If this feature were present in a pure astrocytoma, that would be sufficient to UPGRADE THE LESION, often to ______________; in contrast, in oligodendroglial lineage tumors this histological feature is “allowed” and still compatible with WHO grade III.

Answer 34

WHO grade IV glioblastoma

Question 35

As with ALL WHO grade III tumors, there is significantly MORE___________ than with WHO grade II oligodendrogliomas.

Answer 35

mitotic activity and a higher MIB-1 labeling index

Question 36

more mitotically-active ependymoma than WHO grade II, usually is seen in childhood examples involving the 4th ventricle, and not in adult examples involving the spinal cord

Answer 36

anaplastic ependymoma

Question 37

This is the most common of all gliomas and is also unfortunately the most malignant.

peak incidence for primary GBM is in the 5th to 6th decades

prognosis for these patients remains dismal with median survivals of less than 1 year

Answer 37

glioblastoma

Question 38

What are the diagnostic criteria for GBM?

Answer 38

nuclear abnormalities (nuclear atypia, hyperchromatism, variation in nuclear size and shape)
mitotic activity microvascular proliferation necrosis.

Question 39

Why can’t we cure GBMs?

Answer 39

these tumors are infiltrative, heterogeneous, evolve over time in response to the therapies directed at them, and occur in an eloquent organ that doesn’t allow indiscriminate removal of the tumor without severely neurologically impairing the patient. Different cells express different markers.

Question 40

is a malignant embryonal tumor of the cerebellum that usually occurs in children and tends to spread (metastasize) throughout the cerebrospinal fluid pathways.

Answer 40

Medulloblastoma

Question 41

A number of molecular abnormalities have been characterized in medulloblastoma, several of which:

Answer 41

involve the sonic hedgehog (Shh) signaling pathway

Question 42

__________s common among intracranial neoplasms, and the vast majority are WHO grade I. The peak incidence is among women in their 50s.

Answer 42

Meningioma

Question 43

these peripheral or cranial nerve sheath tumors are mostly benign, though a very small percent may degenerate into a malignant form known as a neurofibrosarcoma.

Answer 43

Schwannomas

Question 44

__________ is an autosomal dominant disorder associated with intra- and extracranial Schwann cell tumors. Optic gliomas, astrocytomas, and meningiomas also occur at higher frequency in NF1.

The NF1 gene encodes a protein, neurofibromin that serves to inhibit RAS.

Answer 44

Neurofibromatosis type 1 (NF1)

Question 45

Neurofibromatosis type 2 (NF2) is characterized most commonly by bilateral vestibular schwannomas and multiple meningiomas. The NF2 gene product, merlin, is believed to regulate

Answer 45

cell surface receptor signaling.

Question 46

__________ is an autosomal dominant syndrome caused by mutation in the TSC1 and TSC2 genes. Their protein products, respectively known as hamartin and tuberin, form a complex that inhibits the kinase mTOR, a regulator of cell size/ growth.

characterized by hamartomas and benign neoplasms of the brain and other tissues, including the sub-ependymal giant cell astrocytoma.

Answer 46

Tuberous Sclerosis

Question 47

The five most common primary sites to metastasize to the CNS are:

Answer 47

lung, breast, melanoma, kidney, and GI tract.

Question 48

Summary Statement of Age/Rx

Answer 48

Kids= grade 1 cut it out
23-30= grade 2 biopsy/rad
30-40= grade 3 chemo/rad
50+= grade 4 every gun you got