Pathology of Brain Tumours Flashcards
what do we mean by intracranial pressure?
For pressure to be stable must be (within certain limits) correct amount of brain tissue/blood/CSF
what keeps the brain in place?
thick tough fibrous sheets inside that keep the brain in place
- Falx cerebri
- Tentorium cerebelli
what are the causes of raised intracranial pressure?
Localised lesions eg
Haemorrhage (if localised called a haematoma)
Tumour
Abscess
Generalised pathology eg
Oedema post trauma
whatare localised lesions?
space occupying lesions in head
what are the effect of intracranila space occupying lesions?
amount of tissue increases
raises intra cranial pressure
cause internal shift between intracranial spaces
what are the types of brain herniation?
cingulate central uncal cerebellotonsillar upward transcalvarial
what is a subfalcine herniation?
midline shift
what is the result of a tentorial (uncal) herniation?
brain herniates inferiorly at side of tentoriuim
aqueduct is crushed and narrow
what is the cause of brain stem death?
cerebellar tonsillar herniation
what are the effects of cerebellar tonsillar herniation?
tonsils move downwards and inwards and crush brainstem
what does swelling and shifting of tumours result in?
ischaemia
symptoms of squeeze on cortex and brainstem?
morning headaches and sickness
symptoms of squeezing on the optic nerve?
papilloedema
what causes pupillary dilation?
squeeze and stretch on cranial nerve 3
what would cause falling glasgow coma scale?
squeeze on cortex and brainstem
what are the primary malignant intracranial tumours?
Glial cells – gliomas (glioblastoma, astrocytoma, oligodendroglioma, ependymoma)
what are the primary childhood malignant intracranial tumour?
Embryonic neural cells – medulloblastoma
what are the primary intracranial tumours surrounding or originating outside the brain?
Arachnoidal cell – meningioma Nerve sheath cell – Schwannoma, neurofibroma Pituitary gland - adenoma Lymphoid cell – lymphoma Capillary vessels - haemangioblastoma
where is the site of CNS tumours in adults?
Majority above tentorium
where is the site of CNS tumours in children?
below tentorium
what are gliomas?
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
what are the various types of gliomas?
Astrocytoma
what are the 2 types of astrocytomas?
- Low grade astrocytoma
2. Glioblastoma
characteristics of low grade astrocytoma?
Bland cells on microscopy (similar to normal astrocytes)
Grow very slowly
what are the most malignant astricytoma?
glioblastoma
characteristics of glioblastoma?
Cellular, atypical tumour, with necrosis under microscope
Grow quickly – often present as large tumours
what is the medulloblastoma?
Tumour of primitive neuroectoderm (primitive neural cells)
Sheets of small undifferentiated cells
Children especially
Posterior fossa, especially brainstem
characteristics of meningioma?
Slow growing
Often resectable
what is the calcification on meningioma sometimes called?
psammoma
where are nerve sheath tumours?
Around peripheral nerves – intracranial and extracranial
Schwannoma is one example
characteristics of schwannoma?
8th vestibulocochlear nerve schwannoma, often called ‘Acoustic neuroma’ at angle between pons and cerebellum
Unilateral deafness
Benign lesion but removal technically difficult
characteristics of pituitary adenoma?
Benign tumour of pituitary in pituitary fossa
Often secrete a pituitary hormone
Grow superiorly and impinge on optic chiasma – visual signs
characteristics of CNS lymphoma?
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
what is haemangioblastoma?
Tumour of blood vessels
Space occupying
May bleed
Most often in cerebellum
