Pathology of Brain Tumours Flashcards Preview

Systems Nervous System > Pathology of Brain Tumours > Flashcards

Flashcards in Pathology of Brain Tumours Deck (44)
Loading flashcards...
1
Q

What determines intracranial pressure?

A

Brain tissue

Blood

CSF

2
Q

How can the brain move with relation to the falx cerebri and the foramen magnum?

A

Brain cannot go through the falx but can go round the edge

Brain cannot go through the skull but can move down through the foramen magnum

3
Q

What are causes of raised intracranial pressure?

A

Haemorrhage

Tumour

Abscess

Generalised pathology (e.g - oedema)

4
Q

What are the SOL? (space occupying lesions)

A

Tumours

Bleeding

Abscess

5
Q

What is the effect of an intracranial space occupying lesion?

A

Increase in tissue

Increase in intracranial pressure

Internal herniation between the intracranial spaces:

Cerebrum moves inferiorly over the edge of tentorium (uncal herniation)

Cerebellum moves inferiorly into foramen magnum (coning)

6
Q

What is subfalcine herniation?

A

Cingulate gyrus herniates underneath falx

Lateral ventricle is crushed flat and is displaced downwards

7
Q

What is uncal herniation?

A

Brain herniates inferiorly at side of tentorium

Aqueduct is crushed and narrow

8
Q

What is the cause of brainstem death?

A

Cerebellar tonsillar herniation

Tonsils move inwards an downwards and crush the brainstem

9
Q

What is the effect of swelling on blood supply?

A

Tumours squeeze nearby tissue and cause local ischaemia

10
Q

What are the symptoms of raised intracranial pressure?

A

Morning headaches and sickness as a result of squeeze on the cortex and the brainstem

Papilloedema (optic disk swelling) - squeeze on optic nerve

11
Q

Why do the pupils dilate during raised intracranial pressure?

A

Squeeze and stretch on cranial nerve 3

12
Q

Why is there a fall on the glasgow coma scale during an increase in the intracranial pressure?

A

There is a squeeze on the cortex and the brainstem

13
Q

To recap pressure increase results in?

A

Pupillary dilation

Falling glasgow coma scale

Brainstem death

14
Q

What are the classifications of intracranial tumours?

A

Primary tumours

Secondary tumours (metastatic tumours)

Other intracranial tumours (cells originating outside the brain and the spinal cord (eg meningioma))

15
Q

What are the types of primary intracranial tumours that arise from brain cells?

A

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

Embryonic neural cells: medulloblastoma

16
Q

What are the primary brain tumours that arise from cells surrounding or originating outside the brain?

A

Arachnoidal cell - meningioma

Nerve sheath cell - schwannoma, neurofibroma

Pituitary gland - adenoma

Lymphoid cell - lymphoma

Capillary vessel - haemangioblastoma

For intradural think of LEMON (LMN)

Lipoma

Meningioma

Neurofibroma

For intramedullary think HEAT:

Haemangioblastoma

Ependymoma

Astrocytoma

Teratoma

17
Q

What is the childhood malignant tumour?

A

Medulloblastoma

18
Q

Where are the central nervous system tumours for adults and children?

A

Adults - majority are above the tentorium

Children - majority are below the tentorium

19
Q

What are the features of a glioma?

A

Resembles cells of glial differentiation

Difuse edges - not encapsulated

Malignant but do not metastasise outside the CNS

20
Q

Where does metastatic malignancy in the brain arise from?

A

Breast

Lung

Kidney

Colon

Melanoma

21
Q

What cells do gliomas resemble?

A

The cells of glial differentiation

Astrocytes - astrocytoma - including glioblastoma

Oligodendrocytes - oligodendroglima

Ependymal cells - ependymoma

22
Q

What is an example of an astrocytoma?

A

Glioblastoma

23
Q

What is the shape of an astrocyte?

A

Star shaped cell

24
Q

What are the features of astrocytomas?

A

Bland cells on microscopy (similar to normal astrocytes)

Grow very slowly

Small cell with single nucleus

25
Q

What is the most malignant?

A

Glioblastoma - not to be confused with low grade astrocytoma as described previously

26
Q

What are the features of glioblastoma?

A

Cellular, atypical tumour with necrosis under the microscope

Grow quickly - often present as large tumours

LARGE CELL WITH MULTIPLE NUCLEI
LARGE CELL WITH IRREGULAR NUCLEUS

27
Q

What is the medulloblastoma a tumour of?

A

It is a tumour of the primitive neuroectoderm (primitive neural cells)

28
Q

What are the features of medulloblastoma?

A

Sheets of small undiferentiated cells

Affects children especially

Situated in the posterior fossa, especially the brainstem

29
Q

What forms from arachnocytes?

A

Meningiomas

Arachnocytes are cells tha make up the covering of the brain

30
Q

Where can you find meningiomas?

A

They are benign and do not metastasise but can be locally aggressive and can invade the skull

31
Q

What are the features of meningiomas?

A

Slow growing

Often resectable

Small groups of cells gather and resemble an arachnoid granulation

Sometimes the cells calcify

The calcification is sometimes called psammoma meaning grain of sand

32
Q

Where can you find nerve sheath tumours?

A

Intracranial and extracranial

33
Q

Give an example of a schwannoma

A

8th vestibulocochlear nerve schwannoma - often called acoustic neuroma - found at the angle between the pons and the cerebellum

34
Q

What are the features of an acoustic neuroma?

A

Unilateral deafness

Benign lesion but removal is difficult

35
Q

Is a pituitary tumour benign or malignant?

A

Benign

Tumour of the pituitary in the pituitary fossa

36
Q

What are the features of a pituitary tumour?

A

Often secrete pituitary hormone

Grow superiorly and impinge on optic chiasma - visual signs (bitemporal hemianopia)

37
Q

What type of cell makes up a CNS lymphoma usually?

A

Usually large B-Cell lymphoma

38
Q

Where in the brain do you find CNS lymphomas?

A

Often deep and central site in the brain

They generally do not spread outside of the CNS

39
Q

Why are CNS lymphomas hard to treat?

A

Drugs do not cross the blood rbain barrier and they are difficult to biopsy

40
Q

What are the complications associated with haemangioblastoma?

A

May bleed

41
Q

Where do you find haemangioblastomas?

A

Most often in the cerebellum

42
Q

What are the features of secondary tumours?

A

Mostly carcinomas

Common

Histology - that of the primary tumour

43
Q

Learning objectives

A
  • Demonstrate understanding of raised intracranial pressure
  • Know symptoms/signs/consequences of raised intracranial pressure
  • Classify intracranial neoplasms
  • Concentrate initial learning on astrocytoma (including glioblastoma) /meningioma/schwannoma and pituitary adenoma
44
Q
A

Decks in Systems Nervous System Class (48):