6/15- Neuro-oncology II Flashcards Preview

Term 5: Neuro > 6/15- Neuro-oncology II > Flashcards

Flashcards in 6/15- Neuro-oncology II Deck (52):
1

What is the most common primitive neuroectodermal tumor of the brain?

Medulloblastoma

2

What are the major gliomas?

- Astrocytomas

- Oligodendroglioma

- Ependymoma

3

What is the importance of the 1p/19q co-deletion?

Prognostic indicator in oligodendrogliomas

4

Breakdown of different types of neural tumors (flowchart)

A image thumb
5

What tumors are grade IV?

- PNET: medulloblastoma

- Glioblsatoma multiforme

6

What is the grade I tumor primarily focused on in this lecture?

- Juvenile pilocytic astrocytomas

7

What demographic is most commonly afflicted with medulloblastomas?

2nd most common?

- Common childhood brain tumor

- Second peak in young adults

8

What is this? Symptoms?

Q image thumb

Medulloblastoma

- Tends to arise in posterior fossa

- In scan, can see midline hyperdensity

- In gross specimen, can see tumor draping over pons arising mostly from the ventricles

- Would initially see midline (vermal) ataxia, followed by limbs

9

The word "anaplastic" identifies the tumor as what?

Grade III

10

Which of the "big 4" tumors commonly arise in the ventricles?

- Ependymoma

- Medulloblastoma

11

What is this? Features? 

Q image thumb

"Small blue cell tumor" (Medulloblastoma)

- Hypercellularity (too many cells)

- Little/no cytoplasm

- Very irregular nuclei (in size and shape); "nuclear pleomorphism" or "nuclear atypia"

- Tumors can start to show some features indicating that they're trying to differentiate

(Homer-Wright rosette- central space within circle-forming cell indicating early differentiation of this primitive neuroectodermal tissue. Indicates that this is a medulloblastoma; bottom-left picture)

12

What is this? 

Q image thumb

Tumor cells that have broken loose and gotten into CSF, "drop metastases"

- Medulloblastoma in CSF (CSF cytology)

- Can see that they're even trying to forma Homer-Wright rosette here (upper)

13

What is this? 

Q image thumb

Glioblastoma multiforme crossing the midline via the corpus callosum

- No distinct borders; terribly infiltrative

- Fast-growing

- These tumors love to cross at the corpus callosum

- Pattern of growth known as "butterfly glioma"

14

What is this? 

Q image thumb

Glioblastoma multiforme

- Terribly fast growing!

- Additional tumor, edema

- Dark areas are probably necrosis within tumor (growing so fast that they outstrip blood supply)

15

What is this? Symptoms? 

Q image thumb

Diffuse intrinsic glioma of the brainstem (one of the big 4 childhood tumors)

- Maybe some cerebellar ataxia

- Probably will spread to pick off cranial nerves

16

What is one of the most common gliomas in adulthood?

Glioblastoma multiforme

17

T/F: Glioblastomas can occur in the posterior fossa

True; see past picture of DIG in the brainstem

18

What is this?

Q image thumb

Glioblastoma multiforme histopathology

- Hypercellularity

2 key histological features to diagnose glioma as glioblastoma (grade IV):

- Vascular proliferation- subset of tumor cells have mutated, allowing them to stimulate new vessel growth; very unregulated, no tight junctions (will leak contrast) (top L darker circles and top R)

- Necrosis- outstripping blood supply (bottom L, bottom R); cells lining up at area of necrosis

19

What is this? 

Q image thumb

Glioblastoma multiforme

- Can't really tell what these are other than just big, bad tumor cells ("monster cells")

- Cell on the left is multinucleate

- To prove it's a glioma, need to stain with GFAP

20

What is this? 

Q image thumb

("Monstrocellular") Glioblastoma multiforme

- GFAP imunopositive

21

What is this? 

Q image thumb

Glioblastoma multiforme with extreme cellular pleomorphism

- High potential for mutation (radiation/chemo resistance)

22

What is this? Expected symptoms?

Q image thumb

Anaplastic astrocytoma (found on histology)

- Squished ventricle

- Abnormality down in temporal lobe

- No distinct border; infiltrative

- Like glioblastoma, but no vascularization and no necrosis

Symptoms:

- Loss of hearing

- Memory disturbances

- Partial complex seizure (often associated with olfactory aura; clouding of consciousness)

23

What is this?

Q image thumb

Anaplastic astrocytoma

- Hypercellularity (normal in top left)

24

What is this? 

Q image thumb

Anaplastic astrocytoma

- Hypercellular

- Can see 5 mitoses (mitotically active)

- No vascularity (see normal BV in bottom right), or necrosis

- May progress to glioblastoma (since mutationally active)

25

Common treatment for glioblastoma (and anaplastic astrocytoma)?

- Debulk via surgery

- Radiation therapy

- Tenozolidimide

26

What is this? 

Q image thumb

Anaplastic astrocytoma

27

What is this? 

Q image thumb

Low grade astrocytoma (normal top left)

- Slight hypercellularity

- Variation and nuclear morphology (subtly nuclear atypy)

- If you start to see mitotic activity, then it moves up to anaplasty

- Low grade astroyctoma may progress into anaplastic and then possibly GBM (glioblastoma multiforme)

- May have partial complex seizures

28

Survival times (with treatment) for glioblastoma multiforme vs. anaplastic astrocytoma?

Glioblastoma multiforme: 12 mo survival on treatment

Anaplastic astrocytoma: 24-36 mo on treatment

29

Treatment for low grade astrocytoma?

We don't really know; don't want to treat with low therapy with high chance for resistance development

30

What is this? 

Q image thumb

Optic nerve glioma (pilocytic astorcytomas (grade I))

- Can see faint line of dura

- Tumor has spread into subarachnoid space

31

What is this?

Q image thumb

Bilateral optic nerve glioma

- Pilocytic astroytomas (grade I)

- Will take vision but typically not kill you (unless in hypothalamus)

32

What is this? 

Q image thumb

Pilocytic astrocytoma

- Hypercelluarity

- Thick process (pear-like) -> "pylocytic"

- Reddish, amorphous, cork-screw like collections (Rosenthal fiber)

33

Characteristics of pilocytic astrocytoma?

- Well circumscribed

- Rarely infiltrative

34

What is this? 

Q image thumb

Infiltrating glioma

- Intraparenchymal (intra-axial) contrast enhancing mass without distinct borders

- Astrocytoma is likely (must differentiate from oligodendroglioma) ?

35

What is this? 

Q image thumb

Oligodendrolgioma, grade II (analogous to astrocytomas grade II)

- "Fried egg" cells

36

What is seen in the molecular biology of oligodendroglioma?

Features tied in with outcome?

Loss of heterozygosity 19q and 1p

- Recent studies indicate that a clinically significant subset of oligodendroglial tumors show co-deletion on chromsomes 1p and 19q

- Response to therapy is much better in pts with co-deletion 1p/19q

37

What is the difference is seen in the mean survival of pts with different 1p/19q characteristics?

- Not co-deleted: 12 mo (1 yr)

- Co-deleted: 124 mo (10 yrs)

38

Treatment for oligodendroglioma?

Combination chemo-therapy with regimens such as PCF or single drug temozolamide with/without radiation (XRT)

(PCV: procarbazine; CCNU and vincristine)

39

What is this? 

Q image thumb

Ependymom

- Intraventricular or in association with central canal of SC

- 4th ventricular tumor on L picture (obstructive symptoms)

40

What is a key difference in medulloblastomas and epndymomas that both can arise in 4th ventricles?

- Medulloblastoma is way faster-growing

- Ependymoma tumors will try to create little ventricles

41

Which tumors are typically more easily removed (surgically resectable)?

- Pilocytic astrocytoma

- Ependymoma

42

What is this? 

Q image thumb

Ependymoma in 4th ventricle

43

What is a risk of both medulloblastomas and ependymomas?

Dissemination through CSF (since in contact); more commonly happens with medulloblastomas

44

What is this? 

Q image thumb

Epnedymoma disseminated through ventricular system

45

What is this? 

Q image thumb

Ventricular tubule with a lumen (tiny ventricle)

- Ependymoma (?)

46

What is this? 

Q image thumb

Perivascular paucinuclear zone with surrounding cells

- Very commonly seen in ependymomas

47

What is seen ultrastructurally in ependymomas?

- Tight junctions

- Cilia

A image thumb
48

What is this?

Grade?

Origin?

Symptoms?

Q image thumb

Colloid cyst of the 3rd ventricle (grape-like structure)

- Grade I

- Arises from ependyma (modified- ependyma)

- Positional hydrocephalus may result in sudden death (but typically, doesn't cause too much trouble)

49

What is this? 

Q image thumb

Colloid cyst of the 3rd ventricle

50

What is this? 

Q image thumb

Central neurocytoma

- Intraventricular mature neuronal tumor

- ("cytoma" typically means more mature)

51

What is this?

Q image thumb

Central neurocytoma

- Clear halo cells-oligo-like

- Neuronal features by EM and immunohistochemistry

52

4 main childhood tumors?

- Medulloblastoma

- ?

- Ependymoma

- Pontine glioma (diffuse intrinsic glioma of pons)