Pathology of Brain Tumours Flashcards
What is the main pathology of brain tumours?
Raised intracranial pressure
What is the cranium?
Hard, rigid box with thick fibrous sheets inside that keeps the brain in place
What are the thick fibrous sheets in the cranium called?
- Falx cerebri
- Tentorium cerebelli
What is the opening in the cranium called for the spinal cord?
Foramen magnum
What happens to the brain during extreme raised ICP?
The brain cannot go through the falx, but can go around the edge, it can not go through the skull, but can move down through the foramen magnum
Is the brain mobile?
Brain is soft, like a jelly, so it moves easily
What are some causes of raised intracranial pressure?
- Localised lesions
- Haemorrhage (if localised called a haematoma)
- Tumour
- Abscess
- Generalised pathology
- Oedema post trauma
What are localised lesions that cause raised intracranial pressure?
Space occupying lesions (SOL)
What does SOL stand for?
Space occupying lesiosn
What are examples of SOH?
- Tumours
- Bleeding (haematoma)
- Abscess
What are effects of SOL?
- Amount of tissue increases
- Raises intracranial pressure
- Cause internal shift (herniation) between the intracranial spaces
- Right-left or left-right
- Cerebrum moves inferiorly over edge of tentorium (uncul herniation)
- Cerebellum moves inferiorly into foramen magnum (coning)
What is coning?
Cerebellum moves inferiorly into foramen magnum
What is uncul hernation?
Cerebrum moves inferiorly over edge of tentorium
What is a haematoma?
Solid swelling of clotted blood within tissues
What are the different types of brain herniation?
What kind of shift does subfalcine herniation cause?
Subfalcine herniation causes midline shift:
- Brian is pushed away from tumour
- Cingulate gyrus is pushed over to side and herniates underneath falx
- Lateral ventricle is crushed flat and displaced downwards
What does tentorial (uncal) herniation cause?
- Brain herniates inferiorly at side of tentorium
- Aqueduct is crushed and narrow
What does cerebellar tonsillar herniation cause?
Cerebellar tonsillar herniation causes death of brain stem due to tonsils moving inwards and downwards, crushing the brainstem
Swelling and shift causes localised ischaemia due to tumours squeezing nearby tissue
What is the presentation of pressure on the brain?
Squeeze on cortex and brainstem:
- Morning headaches and sickness
Squeeze on optic nerve:
- Papilloedema (seen on fundoscopy of the eye)
As pressure increases:
- Pupillary dilation
- Squeeze and stretch on cranial nerve III
- Falling Glasgow coma scale
- Squeeze on cortex and brainstem
- Brain stem death
- Squeezing downwards of cerebellum into foramen magnum with crushing of brainstem
What symptoms does squeeze on the cortex and brainstem cause?
- Morning headaches and sickness
What symptoms does squeeze on optic nerve cause?
- Papilloedema (seen on fundoscopy of the eye)
What is the presentation as pressure on the brain increases?
- Pupillary dilation
- Squeeze and stretch on cranial nerve III
- Falling Glasgow coma scale
- Squeeze on cortex and brainstem
- Brain stem death
- Squeezing downwards of cerebellum into foramen magnum with crushing of brainstem
What are the two broad categories of CNS tumours?
- Primary tumours
- Secondary (metastatic) tumours
Are primary CNS tumours benign or malignant?
Some are benign and some are malignant
What are examples of primary CNS tumours?
- Glial cells
- Gliomas (glioblastoma, astrocytoma, oligodendroglioma, ependymoma) (malignant)
- Embryonic neural cells
- Medulloblastoma (childhood malignant tumour)
- Arachnoidal cell
- Meningioma
- Nerve sheath cell
- Schwannoma, neurofibroma
- Pituitary gland
- Adenoma
- Lymphoid cell
- Lymphoma
- Capillary vessels
- Haemangioblastoma
What are tumours of glial cells called?
Gliomas (glioblastoma, astrocytoma, oligodendroglioma, ependymoma)
What are different kinds of gliomas?
Glioblastoma, astrocytoma, oligodendroglioma, ependymoma
Are gliomas benign or malignant?
Malignant
What are tumours of embryonic neural cells called?
Medulloblastoma
Are medulloblastomas benign or malignant