CNS Tumours

Question 1

Which is the second most common tumour in children after leukaemia?

Answer 1

CNS tumours

Question 2

CNS tumours make up what percentage of malignant neoplasms?

Answer 2

2%

Question 3

Which are the 2 most common types of CNS tumours?

Answer 3

Gliomas and meningiomas

Question 4

What is the age distribution of CNS tumours?

Answer 4

Bimodal - 2 peaks one in childhood, one in adults

Question 5

What is a PNET tumour?

Answer 5

Primitive neuroectodermal tumor (PNET) is a malignant neural crest tumor.

Question 6

What are the most common sight and type of CNS tumours in children?

Answer 6

1) Cerebellum

2) PNET

Question 7

What is the most common sight and which are the 2 most common tumours in adults?

Answer 7

Cerebrum

1) Glioma
2) Meningioma

Question 8

Which is the most common type of CNS tumour in males?

Answer 8

Glioma

Question 9

What is the most common type of CNS tumour in females?

Answer 9

Meningioma

Question 10

What are the 4 types of glial cells and what is their rough function?

Answer 10

1) Astrocytes (support and protect)
2) Oligodendrocytes (myelin)
3) Ependymal cell and choroid plexus cells (CSF)
4) Microglia (defense)

Question 11

What is the difference in treatment for a benign and malignant tumour?

Answer 11

Benign: surgery
Malignant: surgery and adjuvant therapy

Question 12

Do benign tumour recur?

Answer 12

No, tend to get no recurrence with benign tumours

Question 13

What would the grade of a benign brain tumour?

Answer 13

Grade 1

Question 14

What are the 4 histological criteria for malignancy in brain tumour?

Answer 14

1) Cellular density and atypia
2) Mitotic activity (abnormal numbers of mitotic figures)
3) Necrosis (growing so fast some dont get enough resources and die)
4) Vascular proliferation

Question 15

What are the 4 WHO classifications of CNS tumours?

Answer 15

1) Glioma - astrocytoma, oligodendroglioma, ependymoma
2) Meningioma
3) PNET (medulloblastoma)
4) Nerve sheath tumours: schwannoma, neurofibroma

Question 16

Give the 3 microscopical features of astrocytic tumours?

Answer 16

1) Fine fibrillary and microcystic background
2) increased cellular density
3) Pleomorphism (variation in size, shape and chromasia)

Question 17

Give the 4 features of a grade 2 diffuse astrocytoma?

Answer 17

1) Infiltrative, microcystic, fibrillary
2) Low cellular density
3) Mild atypia
4) No mitotic activity

Question 18

Give the 3 features of a grade 3 astrocytoma?

Answer 18

1) Moderate cellular density
2) Moderate pleomorphism
3) Mitoses

Question 19

Give the 3 features of a grade 4 glioblastoma?

Answer 19

1) High cellular density and mitoses
2) Necrosis
3) Vascular proliferation

Question 20

Give the 4 features of a pilocytic astrocytoma, who does it most commonly occur in?

Answer 20

Children (cerebellum)

1) Well defined, cystic
2) Pilocytes
3) Rosenthal fibres
4) Vascular proliferation

Question 21

Give the 3 features of a grade 2 or 3 oligodendroglioma?

Answer 21

1) Round uniform nuclei with clear cytoplasm (fried egg appearance)
2) Arborising capillaries (chicken wire)
3) Calcifications

Question 22

Give the 3 features of an ependymoma grade 2 or 3?

Answer 22

1) Well defined tumour - ventricles
2) Pseudorosettes
3) Round small uniform cells

Question 23

What is the most common group of people and sight of meningioma?

Answer 23

Females - adults

Dura

Question 24

What are the 2 main features of a meningioma?

Answer 24

1) Well defined, extra-axial tumour

2) Whorls, psammoma bodies

Question 25

In which group and sight does a PNET (medulloblastoma) grade 4 most commonly occur?

Answer 25

Children in the cerebellum

Question 26

What are the 4 features of PNET tumours?

Answer 26

1) Very high cellular density
2) Anaplastic hyperchromatic cells
3) Frequent mitoses and apoptosis
4) Rossette formation

Question 27

What is the most common type of nerve sheath tumour?

Answer 27

Schwanomma

Question 28

Schwannoma most commonly occurs on which cranial nerve?

Answer 28

8th cranial nerve

Question 29

Neurofibromas commonly occur in which structures and are rich in what substance?

Answer 29

Spinal nerves

Rich in collagen

Question 30

Radiotherapy treatment can cause which type of brain tumour?

Answer 30

Meningioma

Question 31

Immunosuppression can lead to which tumour?

Answer 31

Lymphoma

Question 32

Which familial syndrome can lead to the development of neurofibroma?

Answer 32

Neurofibromatosis 1

Question 33

Which familial syndrome can lead to the development to schwannoma?

Answer 33

Neurofibromatosis 2

Question 34

What are the 2 properties of stem cells?

Answer 34

1) Self-renewal

2) Differentiation

Question 35

What are the 3 signalling pathways which regulate self renewal during normal stem cell development and during transformation?

Answer 35

1) Wnt
2) Shh
3) Notch

Question 36

A mutation in which signalling pathway can lead to the development of a medulloblastoma?

Answer 36

Shh

Question 37

What is the difference between a primary and secondary glioblastoma?

Answer 37

Primary glioblastoma - formed by a series of mutations in the cell of origin
Secondary glioblastoma - mutations in the cell of origin give rise to astrocytomas, oligoastrocytomas or oligodendroglioma then mutations in these lead to the formation of a secondary glioblastoma

Question 38

Which 4 markers are currently most relevant for molecular diagnostics of glioma (ie. working out the type and grade)?

Answer 38

1) MGMT promoter methylation
2) 1p/2q deletion
3) IGH1/IGH2 mutation
4) BRAF duplication/fusion

Question 39

Other than the histological diagnosis and WHO grade what 5 other factors determine the prognosis of brain tumours?

Answer 39

1) Age: better in younger patients
2) Site
3) Surgical resection
4) Adjuvant therapy
5) Genetic

Question 40

What is the prognosis for a glioblastoma WHO grade 4?

Answer 40

Survival time

Question 41

What is the prognosis for a meningioma WHO grade 1?

Answer 41

Benign