pathology of brain tumours Flashcards
where are the 4 most common sites that a primary tumour can metastasize to the brain from?
lung- 35%
breast- 20%
kidney - 10%
GI tract - 5%
how are brain tumours classified?
tissue of origin
location
primary or secondary
grading
what is a GX grading for a CNS tumour?
grade cannot be assessed
what is a G1 grading for a CNS tumour
well differentiated (low grade)
what is a G2 grading for a CNS tumour?
moderately differentiated (intermediate grade)
what is a G3 grading for a CNS tumour?
poorly differentiated (high grade)
what is a G4 grading for a CNS tumour?
undifferentiated (high grade)
what are some common ways that a brain tumour can present?
neurological deficit 68% motor weakness 45% mental status changes seizures 26% headache 54%
what are some general signs and symptoms of brain tumours?
cerebral oedema increased ICP focal neuro deficits obstruction of CSF flow pituitary dysfunction papilloedema
what are some signs and symptoms that are specific to cerebral tumours?
headache
vomiting NOT related to food intake
changes in visual fields and acuity
hemiparesis or hemiplegia hypokinesia decreased tactile discrimination seizures changes in personality or behaviour
what are som signs and symptoms more specific to brainstem tumours?
hearing loss facial pain and weakness dysphagia, decreased gag reflex nystagmus hoarseness ataxia dysarthria
what are some signs and symptoms more specific to cerebellar tumours?
disturbances in coordination and equilibrium
what are some signs and symptoms more specific to pituitary tumours?
endocrine dysfunction
visual deficits
headache
what are some signs and symptoms more specific to frontal lobe tumours?
inappropriate behaviour personality changes inability to concentrate impaired judgement memory loss headache expressive aphasia motor dysfunctions
what are some signs and symptoms more specific to parietal lobe tumours?
paraethesia
loss of 2 part discrimination
visual field deficits
what are some signs and symptoms more specific to temporal lobe tumours?
psychomotor seizures
hallucinations
loss of consciousness without convulsions
what are some signs and symptoms more specific to occipital lobe tumours?
visual disturbances
what are some classifications of intra axial tumours?
gliomas oligodendroglioa ependymomas medulloblastoma CNS lymphoma
what are 3 types of glioma?
astrocytoma
anaplastic astrocytoma
glioblastoma multiforme
where do ependymomas originate from?
lining of the ventricle
what types of patients are CNS lymphomas common in?
immunocompromised patients
what are some classifications of extra axial tumours?
meningioma metastatic acoustic neuromas pituitary adenoma neurofibroma
what do meningiomas arise from?
arachnoid cap cell types from the arachnoid membrane
are meningiomas usually non invasive?
yes
where are some common locations for meningiomas?
parasagittal region
sphenoid wing
parasellar region
how do meningiomas present?
asymptomatic
focal or generalized seizure
gradually worsening neurological deficit
what is a defining characteristic of meningiomas when contrast is increased on MRI and CT?
they become enhanced with contrast
do diffuse low grade astrocytomas infiltrate surrounding tissue?
yes, widely
where in the brain do diffuse low grade astrocytomas present?
frontal region in the subcortical white matter
how do diffuse low grade astrocytomas present?
seizures
headaches
slowly progressive neurological deficits
do diffuse low grade astrocytomas enhance with contrast when imaged?
not usually
what is more sensitive when attempting to stage a diffuse low grade astrocytoma - CT or MRI?
MRI
how does a glioblastoma infiltrate?
along white matter (can cross the corpus callosum)
where do glioblastomas present?
frontal and temporal lobes
basal ganglia
how do glioblastomas present?
seizures
headache
slowly progressive neurologic deficits
what are some features of a glioblastoma when viewed on a CT?
hypodense/isodense
central hypodense area of necrosis surrounded by thick enhancing rim
surrounding oedema
how are oligodendrogliomas distinguished from astrocytomas?
“fried egg” appearance
what do oligodendrogliomas arise from?
myelin
where are oligodendrogliomas located?
superficially in frontal lobes
how do oligodendrogliomas present?
seizures most common
headache
slowly progressive neurologic deficits
how do oligodendrogliomas look on a CT?
well circumscribed, hypodense lesions with heavy calcification
cystic degeneration of common but haemorrhage and oedema are uncommon
what are some features of a CNS lymphoma?
B lymphocytes
increased ICP
brain destruction
what can cause haemorrhagic brain mets?
melanoma
renal cell
choriocarcinoma
what are some imaging modalities that can be used to diagnose brain tumours?
CT scan with/without contrast MRI with/without contrast plain films myelography PET scan
what kind of tumours might a CT scan miss?
small tumours
brain stem tumours
low grade astrocytomas
tumours adjacent to bone
what are some post op complications that may arise from removal of a brain tumour?
raised ICP hypovolemic shock hydrocephalus atelectasis pulmonary oedema meningitis CSF leak seizures
