Lecture 35: Pathology of Brain Tumour

Question 1

Causes of raised ICP?

Answer 1

Localised (Space Occupying) Lesions

• Haemorrhage or haematoma
• Tumour
• Abscess

Also Oedema post trauma

Question 2

Types of herniation due to raised ICP?

Answer 2

Internal Shift or Herniation:

• Right-left e.g. subfalcine herniation (cingulate gyrus herniates under falx)
• Uncal Herniation (cerebrum moves down over tentorium)
• Coning (Cerebellum, mainly tonsils, moves into foramen magnum)

Question 3

What happens to tissue around a tumour?

Answer 3

Ischaemia due to the squashing effect of the tumour

Question 4

Early signs of a raising ICP?

Answer 4

Morning Headaches and vomiting from cortex/brainstem compression

Papilloedema & Visual Disturbance from pressure on optic nerve

Question 5

What other signs appear as ICP increases?

Answer 5

• Pupillary Dilation from stretch on III
• 6th nerve palsy
• Focal Neurological Deficits
• Falling GCS from pressure on Cortex/brainstem
• Brain Stem Death from coning

Question 6

Intracranial tumours can be divided into 3 major categories?

Answer 6

• Primary CNS tumours
• Secondary (Metastatic) CNS tumours
• Cells from outside CNS e.g. Meningioma

Question 7

What are the classes of Primary tumours?

Answer 7

These Ones are CNS tumours and are malignant:

• Gliomas (many types based on specific glial cell)
• Medulloblastoma (Embryonic Neural Cells)

These are the ones originating outside the brain:

• Meningioma (Arachnoid)
• Schwannoma/Neurofibroma (nerve sheath(
• Adenoma (Pituitary)
• Lymphoma
• Haemanioblastoma (Capillaries)

Question 8

What cancers commonly metastasise to the brain?

Answer 8

• Breast
• Lung
• Kidney
• Colon
• Melanoma

Question 9

where anatomically in the brain would you find tumours?

Answer 9

Adults - Above Tentorium

Children - Mainly below Tentorium

Question 10

Describe Gliomas?

Answer 10

Originate from Glial Cells e.g. Astrocytoma or Glioblastoma

They have no capsule so diffuse edges
They are malignant but do not metastasise outside the CNS

Question 11

What cell do glioblastomas and astrocytomas originate from?

Answer 11

Both from Astrocytes

Question 12

Whats the difference between a glioblastoma and an astrocytoma?

Answer 12

Both originate from astrocytes & are malignant

Astrocytomas:

• Bland mostly normal cells
• Low Grade tumour
• Grows very slowly

Glioblastoma:

• Cellularly Atypical (multiple or irregular nuclei)
• Grows very quickly
• Shows necrosis microscopically

Question 13

What does a medulloblastoma originate from?

Answer 13

Primitive Neuroectoderm (primitive Neural cells)

Question 14

Describe a medulloblastoma?

Answer 14

• Forms sheets of small undifferentiated cells

- Malignant

Question 15

Where and in who do medulloblastomas appear?

Answer 15

• Mostly in children

- In Posterior Fossa especially around the brainstem

Question 16

Describe the growth of a meningioma?

Answer 16

Originates in arachnocytes

They’re benign so no metastases but may invade skull or crush brain

Grows slowly making it often resectable

Question 17

how does a meningioma appear microscopically?

Answer 17

Bland cells in small groups +/- calcification

They tend to resemble a normal arachnoid granulation

Question 18

What do we call the calcifications of a meningioma?

Answer 18

Psammoma body formation

Question 19

Give one major example of a schwannoma and where is it often found?

Answer 19

VIII nerve Schwannoma (Acoustic Neuroma)

Generally at angle of Pons & Cerebellum

Question 20

What are the consequences of an Acoustic

Neuroma?

Answer 20

• Unilateral Deafness
• Benign lesion very difficult to remove

Can also put pressure on facial nerve

Question 21

What does a pituitary adenoma do?

Answer 21

• Impinge on optic chiasm

- Pituitary hormone secretion

Question 22

What makes up a CNS lymphoma?

Answer 22

Diffuse Large B-cell lymphoma

Question 23

Consequences of haemangioblastoma?

Answer 23

Space occupying and may bleed

Question 24

What makes up most secondary tumours in the brain?

Answer 24

Carcinomas

Question 25

Clinical Presentation of Intracranial Tumours?

Answer 25

• Symptoms/signs of raised ICP
• Focal Neurological Deficits
• Seizures (in lesions of cerebral cortex, think tumour in an adult onset seizure)
• CSF obstruction (Hydrocephalus)

Question 26

How would we investigate a suspected Intracranial Tumour?

Answer 26

• History/exam
• CT/MRI
• PET scan
• Biopsy
• Check for sources of secondary tumour e.g. CXR/AXR/PXR

Question 27

What are the goals of Intracranial tumour management?

Answer 27

• Diagnosis of benign vs malignant
• Improve quality of life (reducing symptoms and neurological deficits)
• Prolonging life expectancy

Question 28

What treatments are available for Intracranial Tumours?

Answer 28

• Chemo/radiotherapy

Surgery

• Either as complete resection
• Or debulking to reduce symptoms/ICP

Supportive:
 Corticosteroids (reduces ICP from oedema)
- Anti-epileptics to prevent seizures
- Analgesia
- Anti-emetics

Question 29

Treatment for meningiomas

Answer 29

Usually surgically resectable

May need anticonvulsants

Question 30

Prognosis for Gliomas?

Answer 30

Astrocytomas have a long life expectancy

Glioblastoma Multiformes have a 1yr survival avg.