CNS tumours Flashcards
cerebral tumoours mainly come from two cell types- what are these?
Arachnoidal cells - Meningioma Stem cells - Neurons → ganglioglioma - Astrocytes → Astrocytoma, GBM - Oligodendrocytes -→ oligodendroglioma Metastases - Carcinoma - Sarcoma - Melanoma
What kind of tumours do ARACHNOIDAL CELLS cause?
Meningioma
What kind of tumours do STEM CELLS cause?
- Neurons → ganglioglioma
- Astrocytes → Astrocytoma, GBM
- Oligodendrocytes -→ oligodendroglioma
What kind of metastases can appear as tumours
Carcinoma
- Sarcoma
- Melanoma
whst are the 4 clinical features associated with tumour in cns
4 main features:
- Raised ICP
- Epilepsy
- Loss of function
- Sudden death
1- raised icp can be due to 3 things
Enlarging tumour
o Tiny tumour has no real space effect, intracranial px remains normal
o As it becomes larger you get decreased CSF production (as compensation) so the ICP is the same
o At a certain point no further compensation can occur → ICP rises
Peri-tumoural Oedema
o Around the tumour = fluid in the brain neuropil
o The oedema increases the effective tumour size
• Helpful for doctors as they can give steroids which makes oedema go away → can half tumour size (temporary pain relief)
Hydrocephalus
o When the tumour is situated somewhere where it compresses CSF pathways
• Foramen of Monroe, 3rd ventricle, aqueduct, 4th ventricle
o Result is ventricular dilatation (acts as a space occupying lesion)
o → Raised ICP
raised icp causes features:
o Headache o Nausea & vomiting o Papilloedema • because around the optic nerve there is a sleeve of subarachnoid space → increased pressure in subarachnoid space in skull transfers to this, leading to increased pressure in sleeve & disk → venous compression o Slowed Mentation o As it gets worse → Brainstem compression • Raised BP • Drowsiness • Apathy • Coma • Death
2nd clinical feature of cns tumour is epilepsy. why
- Tumour may irritate the surrounding brain, leading to → new onset of epilepsy
cns tumour can cause vried function loss
- Motor function
- Sensation
- Smell
- Vision
- Hearing
- Balance
- Cerebellar function
- Endocrine (hypothalamus or pituitary)
cns tumour can cause sudden death- how?
- Glioblastoma → intra-tumoural bleed → acute brainstem compression → sudden death
o Glioblastoma which has abnormal vessels that bleed
what do you do to diagnose a cns tumour
- Clinical Features: raised ICP, epilepsy, loss of function,
- CT
- MRI
- Biopsy
why biopsy a cns tumour?
- Radiology is not 100% accurate
- Biopsy → tumour type & grade →
- Ideal treatment
o Complete excision
o Debulking: decreasing size, decreases ICP, prolongs life
o Bx + Radiation & Chemotherapy (can be curative in some cases – faster growing tumours)
brain tumour - there are 3 types
Three types
1) Curable by excision
2) Therapy sensitive (radiation or chemo)
3) Therapy insensitive (debulking)
type 1 brain tumour
- Circumscribed
- Spherical (modified) in shape
- Push brain out of the way
- May be excised & cured
- May recur (if you don’t get it all out)
- BUT: Metastases also look like this
What are the commonest Grade 1 brain tumours
Meningioma
- Benign, slow growing
- Arachnoidal cells
- Adults
- Females 3:2
- May be peripheral or central
