Brain tumors of childhood

Question 1

What are the brain tumors of childhood (5)

Answer 1

1) Pilocytic Astrocytoma
2) Craniopharyngioma
3) Choroid Plexus tumors
4) Medulloblastoma
5) Ependymoma

Question 2

What are the Grade 1 tumors of childhood (3)

Answer 2

1) Pilocytic Astrocytoma
2) Craniopharyngioma
3) Choroid plexus papilloma

Question 3

What is the Grade 2 tumor of childhood?

Answer 3

Ependymoma

Question 4

What is the Grade 3 tumor of childhood?

Answer 4

Choroid plexus carcinoma

Question 5

What is the Grade 4 tumor of childhood?

Answer 5

Medulloblastoma

Question 6

What is the definition of Grade 1?

Answer 6

Benign, slow growing, normal-looking histology. Long term survival expected. Rare in adults

Question 7

What is the definition of Grade 2?

Answer 7

Relatively slow growing, some tumor spread, recurs after removal often higher grade. Slightly abnormal histology

Question 8

What is the definition of Grade 3?

Answer 8

Malignant, tumor spreads, abnormal histology, recurs after removal often higher grade

Question 9

What is the definition of Grade 4?

Answer 9

Malignant, grows quickly, spreads widely, very abnormal histology, angiogenesis and necrosis present

Question 10

What is the #1 brain tumor that’s not of neuroepithelial origin? What’s the embryological structure that forms it?

Answer 10

Craniopharyngiomas are formed from Rathke’s pouch (epithelial origin). Most are suprasellar (above the sella turcica) but can have an intrasellar component

Question 11

Where do pilocytic astrocytomas form?

Answer 11

Centralized location and Periventricular (mostly 3rd ventricle). Also in cerebellum

Question 12

Pilocytic astrocytomas form in which trisomies?

Answer 12

Trisomy 7 and 8

Question 13

What is the gross appearance of pilocytic astrocytomas?

Answer 13

Well circumscribed cystic lesion with a mural nodule

Question 14

What is the histology of pilocytic astrocytoma?

Answer 14

Spindly and elongated astrocytes with Rosenthal fibers

Question 15

What are Rosenthal fibers?

Answer 15

Thick eosinophilic corkscrew bundles on H&E

Question 16

What is the marker for pilocytic astrocytoma

Answer 16

GFAP

Question 17

What is the gross appearance of craniopharyngioma?

Answer 17

Well defined lobulated mass with cyst formation. “Car oil” is present in the cyst

Question 18

What is the histology of craniopharyngioma?

Answer 18

Stratified squamous epithelium with keratin and CALCIFICATIONS

Question 19

In which ventricles do choroid plexues tumors grow?

Answer 19

Lateral and fourth ventricles

Question 20

What genetic syndrome has a propensity to develop choroid plexus tumors?

Answer 20

Li-Fraumeni syndrome (p53 mutation)

Question 21

What is the histology of choroid plexus adenomas?

Answer 21

Fibrovascular connective tissue fronds (blood vessel within connective tissue) and a single layer of columnar epithelium

Question 22

What % of choroid plexus tumors are carcinomas instead of papillomas?

Answer 22

1% are carcinomas

Question 23

What are the markers for choroid plexus tumors?

Answer 23

Epithelial membrane antigen and carotenes

Question 24

What is a common presenting sign for pts with choroid plexus tumors?

Answer 24

hydrocephalus

Question 25

What is the #1 solid brain tumor of kids?

Answer 25

Medulloblastoma

Question 26

When do classic and neuroblastic medulloblastomas occur?

Answer 26

in kids under 10 years old (classic or neuroblastic)

Question 27

What is the other kind of medulloblastoma? When does it occur?

Answer 27

Desmoplastic. 12-20 years old

Question 28

Where do classic medulloblastomas grow?

Answer 28

Mid cerebellum (vermis)

Question 29

Where do desmoplastic medulloblastomas grow?

Answer 29

Lateral cerebellar hemispheres

Question 30

What is the chromosomal abnormality associated with medulloblastoma?

Answer 30

Isochromosome 17q (both 17q's from either mom or dad but not both); also can have 1q mutations

Question 31

What is the gross appearance of medulloblastoma?

Answer 31

Gray nodular mass that is WELL defined

Question 32

What is the histology of classic medulloblastoma?

Answer 32

Dense undifferentiated cells with little to no cytoplasm (small round blue cells)

Question 33

What is the histology of neuroblastic medulloblastoma?

Answer 33

More differentiated cells with elongated nuclei and rosettes

Question 34

What is the histology of desmoplastic medulloblastoma?

Answer 34

Most differentiated cells with germinal centers

Question 35

What are the markers from medulloblastoma?

Answer 35

Chromogranin, synaptophysin, neurofilaments (remember it's neural not glial so no GFAP)

Question 36

What is the prognosis for medulloblastoma?

Answer 36

Good prognosis even though it is Grade 4

Question 37

What are the two types of ependymomas?

Answer 37

Intratentorial and Spinal

Question 38

When do infratentorial ependymomas occur?

Answer 38

under 10 years old

Question 39

When do spinal ependymomas occur?

Answer 39

pt in their 30s

Question 40

Where do infratentorial ependymomas occur?

Answer 40

4th ventricle near pons

Question 41

Where do spinal ependymomas occur?

Answer 41

Cauda equina

Question 42

What is the mutation associated with ependymomas?

Answer 42

22q mutation

Question 43

What is the gross appearance of ependymomas?

Answer 43

Well demarcated mass with cysts and possible calcifications

Question 44

What is the histology of ependymomas?

Answer 44

Homogeneous cells with cilia in Pseudorosettes and true rosettes

Question 45

What is the pseudorosette in ependymoma called?

Answer 45

Perivascular pseudorosette (tumor cells around a central blood vessel)

Question 46

What are the rosettes called in ependymoma?

Answer 46

True ependymal rosettes - tumor cells around an empty space (little ventricle)

Question 47

What is a common presenting sign with ependymoma?

Answer 47

Hydrocephalus due to obstruction

Question 48

What % of ependymomas are supratentorial?

Answer 48

40%