Pathology of Brain Tumours Flashcards
What is the main effect of brain tumours
Raised intracranial pressure
What is three anatomically feature to consider in intracranial pressure
The cranium is a hard rigid closed box
Falx cerebri/tentorium cerebella -Thick rough fibrous sheet inside
Foramen magnum
How does pressure remain stable in the brain
The correct amount brain tissue, blood and CF within the cranium
What is the causes of raised intracranial pressure
Space occupying lesion (localised)
Generalised pathology
What is three examples of a space occupying lesion that causes raised intracranial pressure
Heamtoma
Tumour
Abscess
What is an examples of a generalised pathology that causes raised intracranial pressure
Post trauma oedema
How does space occupying lesion increase intracranial pressure
The amount of tissue increases there direct correlation increases the intracranial pressure
What is the pathological affect of raised intracranial pressure on the brain
Causes internal shift (herniation) between the intracranial spaces
What are the three directions of herniations that occur
Right- left or left - right
Cerebellum moves inferiorly over edge of tentorium
Cerebellum moves inferiorly into foramen magnum
What is the six different brain herniations
Cingulate (subfalcine)
Central
Uncal (transtentorial)
Cerebellotonsillar
Upward
Transcalvarial
What occurs in cingulate brain herniations
Falx pushed over to side (mid line shift) so the brain pushed away from the tumour
As the cingulate gyrus is pushed over to the side and herniates underneath falxi
What occurs as a result of cingulate hernatio
Lateral ventricles crushed flat and displaced downwards
What cause central herniation and what is the potentially result
occurs when there is downward pressure centrally and can result in bilateral uncal herniation
What is another name for uncal herniation
transtentorial herniation
What occurs in uncal hernation
Brain herniated at the side of the tentorieum
What is the affect of uncal herniation
Aqueduct is crushed and narrow
What occurs in cerebellotonsillar hernation
Cerebellum moved inwards and down into foramen magnum
What is the affect of cerebellotonsilar herniation
as cerebellum tonsils move inwards and downwards and crush brainstem resulting in brain stem death
What occurs in trancalvarial
Brain herniates out of cranium through skull fracture
What occurs as a result of swelling and shift in the brain
Localied ischaemia due to the tumour squeezing the nearby tissue
creating an ischaemia zone around the tumour
What symptoms occurs due to the affect of squeezing on cortex and brain stem
Morning headaches
Sickness
As pressure increases on the cortex and the brain stem what sign can be seen
A fallling score in the Glasgow coma scale
What is the sign seen due to raised intracranial pressure squeezing optic nerve (CN II) and squeezing and stretching occulomotor nerve (CNIII)
CN II - papilloedema
CN III- pupillary dilation
What is the overall symptoms and signs seen for increased pressure eon the brain
Morning headaches
Sickness
Papilloedema
Pupillary dialtion
Decreased Glasgow coma coma scale score
What are common metastatic tumours in the CNS
Breast, Lung, Kidney, Colon, (GI tract) Melanoma
What are two examples of brain cell tumours
Gliomas - Gilal cells
Medullablastoma - Embryonic neural cells
What kind of tumours are gliomas
Malignant tumours - but do not metastases outside the CNS
What is the morphology of gliomas
Resemble cells of glial differentiation
- Astrocyte/
- oligodendrocyte
- ependymal cells
Diffuse edges not encapsulated
What is the main types of gliomas
Astocytoma - astrocyte (glioblastoma)
Oligodendroglioma - ogliodendrocyte
ependymomoa - ependymal cells
What can be seen in a low grade astrocytoma
Bland cells on microscopy similar to star shaped astrocyte cell
Grow very slowly
What can be seen in astrocytoma and glioblastoma under the microscope
cellular, atypical tumour with necrosis
If appear higher grade = glioblastoma
How are astrocytoma and glioblastoma the most malignant glioma
as grow very quickly and are often present as large tumours
What kind of tumour is medullablastoma and what is it derived from
Childhood malignant tumour
tumour derived from primitive neuroctoderm (primitive neural cell)
Where is medullablastoma located
posterior fossa especially the brain stem
Where does medullablastoma metastases
other part of the brain and spinal cord
What is see under the microscope in medullblastoma
sheets of small undifferentiated cells
What tumours, originate from cells surrounding or originating outside the brain
Meningioma
schwannoma
neurofibroma
adenoma
lymphoma
haemangioblastoma
Mengioma is a tumour of what cell
arachnoid cell - cells that make up the covering of the brain
(arachnocytes)
What kind of tumour is meningioma
Benign (slow growing)
meningioma does not metastases but how does it spread
spreadse locally aggressive and invades the skull
What can be seen in the microscopy of meningioma
Bland cells foreign small groups resuming arachnoid granulation
sometimes with calcification
How are meningioma treated
Surgery as often resectable
Schwannoma is a tumour of what cell
Schwann (nerve sheath) cells - which wrap around peripheral nerves and form electrical insulation (myelin sheath)
What is an example of a schwannoma
Acoustic neuroma - 8th vestibulocohlear nerve schwannoma
Where is an acoustic neuroma located,
At angle between pons and cerebellum
What is the symptoms of acoustic neuroma
unilateral deafness
What does the location of acoustic neuroma usually mean
removal is technically difficult
What is adenoma a tumour of
Pituitary gland in pituitary fossa
causes hormone imbalance
What type of tumour is an adenoma
benign
How does an adenoma grow and what affect does this have
Grows superiorly and impinges on optic chiasma causing visual problems
What is a lymphoma a tumour of
Lymphoid tissue
What kind of tumour is lymphoma
High grade neoplasm
of
What specific cell type of lymphoma affects the CNS
Usually diffuse large B- cell lymphoma
Where is lymphoma located in the CNS
Often deep and central site in the brain
What does the usually location of lymphoma usually mean
Difficulty to make biopsy
difficulty yo treat as drugs cannot cross blood brain barrier
How far does lymphoma metastases
Doesn’t spread outside of CNS
What is haemangioblastoma a tumour of
Blood vessels
What is the characteristic os a haemangioblastoma
Is space occupying lesion
May bleed
most often found in the cerebellum
Where are intracranial tumours more likely to be located in adults
majority tumours located above the tentorium
Where are intracranial tumours more likely to be located in
majority tumours located below the tentorium
What is the most common brain tumour seen clinically
Metastases
What is the most aggressive glioma
Glioblastoma multiforme (GBM)
How and where do glioma spread
by tracking through white mater and CSF pathway, don’t metastases outside the CNS
