Pathology of Brain Tumours

Question 1

what do we mean by intracranial pressure?

Answer 1

For pressure to be stable must be (within certain limits) correct amount of brain tissue/blood/CSF

Question 2

what keeps the brain in place?

Answer 2

thick tough fibrous sheets inside that keep the brain in place

• Falx cerebri
• Tentorium cerebelli

Question 3

what are the causes of raised intracranial pressure?

Answer 3

Localised lesions eg
Haemorrhage (if localised called a haematoma)
Tumour
Abscess

Generalised pathology eg
Oedema post trauma

Question 4

whatare localised lesions?

Answer 4

space occupying lesions in head

Question 5

what are the effect of intracranila space occupying lesions?

Answer 5

amount of tissue increases
raises intra cranial pressure
cause internal shift between intracranial spaces

Question 6

what are the types of brain herniation?

Answer 6

cingulate
central
uncal
cerebellotonsillar
upward
transcalvarial

Question 7

what is a subfalcine herniation?

Answer 7

midline shift

Question 8

what is the result of a tentorial (uncal) herniation?

Answer 8

brain herniates inferiorly at side of tentoriuim

aqueduct is crushed and narrow

Question 9

what is the cause of brain stem death?

Answer 9

cerebellar tonsillar herniation

Question 10

what are the effects of cerebellar tonsillar herniation?

Answer 10

tonsils move downwards and inwards and crush brainstem

Question 11

what does swelling and shifting of tumours result in?

Answer 11

ischaemia

Question 12

symptoms of squeeze on cortex and brainstem?

Answer 12

morning headaches and sickness

Question 13

symptoms of squeezing on the optic nerve?

Answer 13

papilloedema

Question 14

what causes pupillary dilation?

Answer 14

squeeze and stretch on cranial nerve 3

Question 15

what would cause falling glasgow coma scale?

Answer 15

squeeze on cortex and brainstem

Question 16

what are the primary malignant intracranial tumours?

Answer 16

Glial cells – gliomas (glioblastoma, astrocytoma, oligodendroglioma, ependymoma)

Question 17

what are the primary childhood malignant intracranial tumour?

Answer 17

Embryonic neural cells – medulloblastoma

Question 18

what are the primary intracranial tumours surrounding or originating outside the brain?

Answer 18

Arachnoidal cell – meningioma
Nerve sheath cell – Schwannoma, neurofibroma
Pituitary gland - adenoma
Lymphoid cell – lymphoma
Capillary vessels - haemangioblastoma

Question 19

where is the site of CNS tumours in adults?

Answer 19

Majority above tentorium

Question 20

where is the site of CNS tumours in children?

Answer 20

below tentorium

Question 21

what are gliomas?

Answer 21

Resemble cells of glial differentiation
Diffuse edges – not encapsulated
Malignant but do not metastasise outside the CNS

Astrocytes–> , astrocytoma (including glioblastoma)
Oligodendrocytes —> oligodendroglioma
Ependymal cells—> ependymoma

Question 22

what are the various types of gliomas?

Answer 22

Astrocytoma

Question 23

what are the 2 types of astrocytomas?

Answer 23

1. Low grade astrocytoma

2. Glioblastoma

Question 24

characteristics of low grade astrocytoma?

Answer 24

Bland cells on microscopy (similar to normal astrocytes)

Grow very slowly

Question 25

what are the most malignant astricytoma?

Answer 25

glioblastoma

Question 26

characteristics of glioblastoma?

Answer 26

Cellular, atypical tumour, with necrosis under microscope | Grow quickly – often present as large tumours

Question 27

what is the medulloblastoma?

Answer 27

Tumour of primitive neuroectoderm (primitive neural cells) Sheets of small undifferentiated cells Children especially Posterior fossa, especially brainstem

Question 28

characteristics of meningioma?

Answer 28

Slow growing | Often resectable

Question 29

what is the calcification on meningioma sometimes called?

Answer 29

psammoma

Question 30

where are nerve sheath tumours?

Answer 30

Around peripheral nerves – intracranial and extracranial | Schwannoma is one example

Question 31

characteristics of schwannoma?

Answer 31

8th vestibulocochlear nerve schwannoma, often called ‘Acoustic neuroma’ at angle between pons and cerebellum Unilateral deafness Benign lesion but removal technically difficult

Question 32

characteristics of pituitary adenoma?

Answer 32

Benign tumour of pituitary in pituitary fossa Often secrete a pituitary hormone Grow superiorly and impinge on optic chiasma – visual signs

Question 33

characteristics of CNS lymphoma?

Answer 33

``` High grade neoplasm Usually diffuse large B-cell lymphoma Often deep and central site in brain Difficult to biopsy Difficult to treat as drug do not cross blood-brain barrier Generally do not spread outside of CNS ```

Question 34

what is haemangioblastoma?

Answer 34

Tumour of blood vessels Space occupying May bleed Most often in cerebellum