Histopathology 18: Neuro-oncology

Question 1

List 4 genetic syndromes responsible for primary CNS tumours ?

Answer 1

Neurofibromatosis 1
Neurofibromatosis 2
Tuberous Sclerosis 1
Tuberous Sclerosis 2
Turbot’s syndrome

Question 2

Outline the WHO grading of CNS tumours ?

Answer 2

Grade 1 : Benign, long-term survival
Grade 2 : causes death in > 5 years
Grade 3 : causes death in < 5 years
Grade 4 : causes death in < 1 year

NB Grade I and II are considered LOW grade

Question 3

What type of tumours are the most common primary CNS tumours ?

Answer 3

Diffuse Gliomas (glial cells)

Question 4

Give 2 examples of Glial tumours in adults ?

Answer 4

Astrocytoma
Oligodendrogliomas

NB diffuse = show a very infiltrative type of growth (become more malignant over time)

Question 5

What’s the most common glial tumour in children ?

Answer 5

Pilocytic astrocytoma (NB this is a circumscribed glioma, not diffuse)

Question 6

What are the typical histological features of Pilocytic Astrocytomas ? (2)

Answer 6

Piloid (hairy) cells
Rosenthal fibres

Question 7

Which tumours do astrocytomas turn into after about 5-7 years ?

Answer 7

Glioblastomas

(It is a Grade 4 astrocytoma)

Question 8

What mutation is most commonly seen in astrocytomas ?

Answer 8

IDH 1/2

Question 9

Describe a typical feature of oligodendroglioma on histology ?

Answer 9

Fried eggs - Round cells with clear cytoplasm

Question 10

Which genetic syndrome is associated with meningiomas ?

Answer 10

Neurofibromatosis 2

Question 11

Where are medulloblastomas always found ?

Answer 11

cerebellum

Question 12

List some symptoms of medulloblastoma ?

Answer 12

ICP symptoms- morning headaches, nause and vomiting, blurry vision

Loss of balance and coordination

Abnormal eye movements

NB cerebellum affected

Question 13

List 3 typical features of medulloblastoma on histology ?

Answer 13

• Small blue round cells (hyperchromatic nuclei with NO cytoplasm)
• Homer-Wright rosettes
• Neuronal marker Synaptophysin positive

Question 14

Where are metastatic brain tumours most commonly found ?

Answer 14

The grey-white junction (where grey and white matter meet)

• This is because the structure of the cerebral blood vessels change at this point (becoming smaller as they enter the white matter)
• Therefore, neoplastic emboli tend to get stuck at this level and then start growing

NB another site = meninges

Question 15

A ventricular tumour presenting with hydrocephalus.

Most likely diagnosis ?

Answer 15

Ependymoma

Question 16

A soft gelatinous, calcified tumour.

Most likely diagnosis ?

Answer 16

Oligodendroma

Question 17

usual inheritance of CNS tumours

Answer 17

autosomal dominant

Question 18

presentation of CNS tumours

Answer 18

• Intracranial Hypertension: headache, vomiting, change in mental state
• supratentorial = focal neurological deficit, seizures, personality changes
• subtentorial = cerebellar ataxia, long tract signs, cranial nerve palsy

Question 19

what chemo is used in high grade gliomas

Answer 19

temozolamide

Question 20

Tumour arising from Embryonal cells

Answer 20

medulloblastoma (2nd most common in children)

Question 21

Most common genetic syndrome related to brain tumours

Answer 21

Neurofibromatosis

Question 22

% of brain tumours due to genetics

Answer 22

<5%

Question 23

Genetics in Diffuse gliomas

Answer 23

IDH 1/2 mutation

Question 24

Genetics in Circumscribed Gliomas

Answer 24

MAPK pathway mutation (BRAF)

Question 25

Pilocytic astrocytoma found in which condition and in which group of pts?

Answer 25

NF1 - CHILDREN

Question 26

Astrocytoma location in brain

Answer 26

Often CEREBELLAR

Question 27

Mutation in **Pilocytic Astrocytoma**

Answer 27

BRAF Mutation (KIAA1549-BRAF fusion)

Question 28

Main site for Diffuse Astrocytoma

Answer 28

Cerebral hemispheres (see on MRI)

Question 29

Most aggressive type of glioblastoma

Answer 29

de novo glioblastoma

Question 30

Mutation in Diffuse Astrocytoma

Answer 30

Mutation in IDH1/2

Question 31

Effect of IDH mutation in Glioblastoma Multiforme

Answer 31

PROTECTIVE * IDH mutation is in astrocytoma, and 10% of glioblastoma arises from astrocytma (so secondary glioblastoma) * So protective in that it is not as bad a primary glioblastoma (without IDH mutation) as this is FAR MORE aggressive

Question 32

Name when glioblastoma spreads to other hemisphere

Answer 32

butterfly tumour

Question 33

Type of necrosis that can be seen in Glioblastoma Multiforme

Answer 33

pallisadian necrosis * there is necrosis surrounded by palisade tumour cells

Question 34

most frequent brain tumour in adults

Answer 34

Metastatic carcinoma

Question 35

most frequent brain tumour in children

Answer 35

Pilocytic astrocytoma

Question 36

What does the tumour grade tell us?

Answer 36

Survival - important prognostic factor

Question 37

24 y/o with long history of neurological signs (usually seizures). Which brain tumour?

Answer 37

Oligodendroglioma * Those between 20-40 years * get long history of neurological signs (usually seizures)

Question 38

Mutation in almost 100% cases of Oligodendroglioma Diagnostic mutation

Answer 38

IDH1/2 mutation Co-deletion 1p/19q (NB this mutation has better prognosis if present)

Question 39

Which has better prognosis, Oligodendroglioma or astrocytomas?

Answer 39

Oligodendroglioma (LESS aggressive and do not progress to a higher grade as quickly)

Question 40

What is the major change in the last WHO (2016) CNS tumour classification?

Answer 40

Incorporation of genetic profile

Question 41

Which mutation identifies the mutation diffuse astrocytic tumours with a better prognosis?

Answer 41

IDH mutation

Question 42

Most common, and 2nd most common, primary intracranial tumours

Answer 42

* Most: gliomas * 2nd: Meningioma

Question 43

Where can you find Meningioma

Answer 43

anywhere in the craniospinal axis

Question 44

Condition where you get multiple meningioma

Answer 44

NF2

Question 45

Grade 2 meningioma is what?

Answer 45

When there is brain invasion

Question 46

Mx of Meningiomas that are grade ≥ II

Answer 46

radiotherapy as well as surgery

Question 47

Important aspect of determining grade of meningioma

Answer 47

Mitotic activity * Grade is based on **mitoses/ 10 high power fields**

Question 48

2nd most common tumour in kids

Answer 48

Medulloblastoma

Question 49

Prognosis of different classifications of medulloblastomas

Answer 49

* **WNT-activated** – VERY GOOD prognosis (often cured with radio/chemotherapy) * **SHH-activated** – Intermediate prognosis * **Non-WNT/non-SHH** – VERY AGGRESSIVE, POOR prognosis \*\*C1 CLOZE DELETE EACH ANSWER PLEASE\*\*