The pathology of intracranial tumours Flashcards
3 space occupying lesions causing raised ICP
haemorrhage - haematoma
tumour
abscess
Generalised pathology causing raised ICP
oedema post trauma
What happens following a SOL?
amount of tissue increases
raised ICP
cause internal shift/herniation between intracranial spaces
3 types of internal shift due to SOL
Right-left or left-right
uncal herniation
coning
What is uncal herniation?
cerebrum moves inferiorly over edge of tentorium
What is coning?
cerebellum moves inferiorly into foramen magnum
What is a subfalcine herniation?
cingulate gyrus pushed side and herniated under falx
What happens to brain, falx, midline and lateral ventricle in subfalcine herniation?
pushed away from tumour
lateral ventricle crushed flat and displaced downwards
midline shift
What happens to aqueduct in uncal herniation?
crushed and narrow
What is cerebellar tonsillar herniation the cause of?
brain stem death
What happens in cerebellar tonsillar herniation?
tonsils move inwards and downwards and crush brainstem
When tumours squeeze nearby tissue what occurs?
ischaemia
Symptoms of squeezing on cortex and brainstem
morning headaches
sickness
Sign of squeezing on optic nerve
papilloedema - fundoscopy
As ICP increases what happens and why?
pupillary dilation - CN 3
falling GCS - cortex and brainstem
brainstem death - crush brainstem
Example of intracranial tumour arising outwith brain and spinal cord
meningioma
Common cancers to metastasise to brain
breast, colon, kidney, lung, melanoma
Difference in usual site of CNS tumours in adults and children
tentorium - adults above and children below
What do gliomas resemble?
cells of glial differentiation
2 features of gliomas
not encapsulated
do not spread outwith CNS
Appearance of low grade astrocytoma
bland cells and grow very slowly
Glioblastoma appearance
cellular, atypical, tumour, necrosis
grow quick and large tumours
What is medulloblastoma a tumour of?
primitive neuroectoderm
Where is medulloblastoma usually located?
posterior fossa - brainstem
What type of people do medulloblastoma usually occur in?
children
What are menigiomas derived from?
arachnocytes
Describe a meningioma
slow growing and resectable
attached to meninges and depress cerebrum
do not metastasise but can be locally invasive and can invade skull
Microscopy of meningioma features
bland cells forming small groups
calcification
What is an acoustic neuroma?
8th cranial nerve schwannoma
Where is an acoustic neuroma found within the brain?
angle between pons and cerebellum
Symptom of acoustic neuroma
unilateral deafness
Is an acoustic neuroma malignant or benign?
benign
What is a pituitary adenoma?
benign tumour of pituitary in pituitary fossa
What signs can occur from a pituitary adenoma?
visual - press on optic chiasm
Why are CNS lymphoma hard to biopsy and treat?
deep in brain
blood-brain barrier
Haemangioblastoma
tumour of blood vessels
Haemangioblastoma - site
cerebellum
Histology of secondary tumours
same as that of primary
