Intracranial tumours Flashcards
What is the age distribution of intracranial tumours?
bimodal
Are males or females more likely to have gliomas?
males
Are males or females more likely to get meningioma?
females
What are the 4 types of glial cells?
- astrocytes
- oligodendrocytes
- ependymal cells and choroid plexus cells
- microglia
What is the function of astrocytes?
support and protection
What is the function of oligodendrocytes?
produce myelin
What is the function of choroid plexus cells and ependymal cells?
CSF production
What is the function of microglia?
defence from pathogens
What is a meningeal tumour called?
meningioma
What is the name of a tumour in the nerve sheath?
schwannoma
What are the two component of a histological diagnosis?
name of tumour and grade
Describe the behaviour of a benign tumour
- slow growing
- respect surrounding tissue
- no/slow progression
- no recurrence
Describe the behaviour of a malignant tumour
- rapid growing
- invade and destroy surrounding tissue
- progress
- recurrent
Describe a grade I tumour
benign, no recurrence, no/very slow progression
Describe a grade II tumour
low grade, progression
Describe a grade II tumour
high grade, rapid progression
Describe a grade IV tumour
aggressive
What are the histological criteria fro malignancy in brain tumour?
- cellular density and atypia
- mitotic activity
- necrosis
- vascular proliferation
What is pleomorphism?
variation in size, shape and chromasia
What are the characteristics of a diffuse astrocytoma II?
- infiltrative, microcystic, fibrillary
- low cellular density
- mild atypia
- NO MITOTIC ACTIVITY (why it’s only grade II)
What are the characteristics of an anaplastic astrocytoma III?
- moderate cellular density
- moderate pleomorphism
- mitoses
What are the characteristics of a meningioma I?
- females, dura, adults
- well-defined extra-axial tumour
- whorls, psammoma bodies
What does PNET stand for?
primitive neuroectodermal tumour
Describe a schwannoma I
- 8th cranial nerve
- biphasic pattern (loose and dense areas)
- reticulin
Which intracranial tumour does radiotherapy raise risk of?
menignioma
What are the 4 markers that are presently the most relevant for molecular diagnostics of gliomas?
- MGMT promotor methylation
- 1p/19q deletion
- IDH1/IDH2 mutation
- BRAF duplication/fusion
what are the symptoms of raised intracranial pressure?
- headaches (early morning)
- vomiting
- blurred vision
what can cause raised ICP?
- tumour mass
- surrounding edema
- obstructive hydrocephalus
Which types of imaging may you use for diagnosis?
- computerised tomographic scan
- magnetic resonance imaging
- cerebral angiography
If there is language loss, where would you expect the tumour to be?
left hemisphere (or whichever is dominant)
Right handed women seems to be understanding but cannot make others understand her, where is the lesion?
left temporo-frontal region
Someone becomes withdrawn, apathetic and bad-tempered then develops headaches and vomiting, where is the lesion?
frontal region
Sensory loss, dyspraxia, inattention, where is the lesion?
parietal lobe
What is radiotherapy?
the use of X-rays to treat tumours - carefully controlled high energy X-ray beams are focused on the tumour
What are the acute side effects of cranial radiotherapy?
- cerebral oedema causing raised ICP and exacerbation of pre-RT neurological symptoms
- hair loss
- scalp/ear erythema
What are the late side effects of radiotherapy?
damage to sensitive structures (eg lens, pituitary, cerebral hemispheres)
Why are steroids used as part of treatment?
reduce swelling around the brain
