Week 4 - I - Brain tumours - Astrocytomas, Oligodendriogliomas, Meningiomas, Acoustic Neuroma, Pinealomas, Pituitary tumours Flashcards
What are brain tumours?
These are tumours described as being primary or secondary, benign or maligannt growth of cells within the brain
What do extra-axial and intra-axial brain tumours mean? What is the most common extra-axial brain tumour?
Extra-axial brain tumour is one that has arisen outside of the brain parenchyma (fucntional brain tissue and spinal cord) - the most common extra-axial brain tumour is the meningioma
Intra-axial brain tumours arise within the brain parencyhma
What do meningiomas arise form?
Meningiomas are usually benign and arise from the arachnoidal cells of the meninges
What is the commonest cause of cancer related deaths in patients under 40? What is the second most most common tumour in children?
Brain tumours are the most common cause of cancer related death in patients under 40 years of age
Primary brain tumours are the second most common tumour in children - second only to leukaemia (typically acute lymphoblastic leukaemia)
`What is the normal presentation of brain tumours? Remember it is a space occupying lesion so think of What nerve palsy is most common in space occupying lesions?
- * Progressive neurological deficit - eg papilloedema
- * Usually motor weakness
- * Headaches
- * Seizures
- * 6th nerve pasly is most common due to long course
- * Progressive neurological deficit 68%
- * Usually motor weakness 45%
- * Headache 54%
- * Seizures 26%
Remember - primary brain tumours second most common in children Number 1 cause of cancer related deaths in those below 40
Why is there an increased intracranial pressure? What can this increase cause as presentation?
Increased intracranial pressure a there is an increase in mass inside a rigid box - the brain is enclosed and not much room for any expansion
Can cause hydrocephalus, headaches, vomiting, seizures, mental changes
Headache -May occur with or without raised ICP When is it typically worse? When does the headache tend to increase?
The headache is typically worse in the mornings and can wake you up
Tends to increase in severity when coughing and bending forward
Also may have an association with vomiting
Why is it that the headaches tend to be worse in the mornings?
This is because the CSF does not drain as well when lying down so a mass in the brain will only further worsen the drainage on top of the pressure - increasing headache
Aetiology of tumour headache Why might a headache arise form a tumour? What vision defects may arise due to the tumour?
May occur due to raised ICP
May occur due to tumour invasion/compression of dura/periosteum secondary to vision defects - diplopia (CN III, IV, VI, INO)
Extreme hypertension
What is internuclear ophthalmoplegia? Hypertension can occur causing headaches when a brain tumour is present due to the effects of Cushings triad What is cushings triad?
When an attempt is made to adduct -(with the relative affected eye), the eye minimally or does not adduct , the contralateral eye however presents with nystagmus
Cushing’s triad is a physiological nervous system response to increased intracranial pressure (ICP) that results in Cushing’s triad of:
- increased blood pressure,
- irregular breathing, and
- bradycardia - ususally because the cerebral perfusion pressure has dropped dramtically
When there is a swollen brain, what herniations of the brain may occur? Describe each of the 4 herniations
- Subfalcine - herniates under the falx cerebri
- Subtentorial (central) - brain herniates under tentorial cerebelli
- Uncal (transtentroial)- lesions herniates towards tentorium and put pressure on the brainstem
- Tonsilar - herniation through foramen magnum - usually fatal here
What effect does uncal herniations have on the oculomotor nerve?
The uncal herniations can compress the parasympathetics that run alongside this nerve resulting in a fixed dilated pupil
Why can inability to abduct either eye be a sign of a space occyping lesion?
CN VI has a long course through the brain and therefore a SOL can compress the nerve throughout its course resulting in diplopia
When there is a lesion in the frontal lobe, what are the symptoms thought to occur? What about a lesion in the temporal lobe? Name at least 3 for each
Frontal lobe:
- * Changes in personality or behaviour
- * Uncoordinated walking
- * Weakness on one side of the body
- * Problems producing speech correctly (Brocas)
- * Also memory problems
Temporal lobe
- * Muddled speech (wernickes - comprehension)
- * Memory
- * Hearing&vision
- * Emotions
What problems can arise due to a parietal lobe lesion? What can arise due to cerebellar disturbance? (DANISH) WHat can arise due to occipital lobe lesion?
Parietal lobe lesion
- * Speech and understanding
- * Writing, reading and simple calculations
- * Finding your way around
- * Sensory loss on one side of the body
Cerebellar
- * D - dysdiadokinesia, A - ataxia, N - nystagmus, I - intention tremor, S - slurred speech, H - hypotonia
Occipital lobe
- * Visual problems
What are the symptoms of a brainstem lesion?
Double vision
Troubles swallowing or breathing
Facial weakness
Dizziness
If in the GP and a patient presents with headache worse in the mornings that wakes them up, as well as changes in behaviour What can you check for in the practice?
You can check for papilloedema in practice here - can be caused by raised intracranial pressure but patient should be referred for neurological examination
What can be given to a patient presenting with cerebral oedema and a raised ICP with a suspected SOL? This can treat the cerebral oedema and raised ICP
Can give dexamethasone + mannitol
After performing a neurological examination, which investigation would be carried out to identify the cause of the space occupying lesions?
CT +/- MRI for tumour detection
What are the two most common cell causes of primary malignant tumour in the brain? Usually tumours arise from different types of glial cells What one is the most common type of brain tumour?
Astrocytes - most common primary brain tumour in UK (60%)
Oligodendroglial cells
WHat is the function of astrocytes? What are the four different grades for astrocytomas?
Astrocytes are involved in maintaining the blood brain barrier and electrolyte balance - they are the stap shaped cell (Astron = star in greek)
- * Grade 1 - pilocytic astrocytoma, pleomoprhic xanthoastrocytoma, subependymal giant cell
- * Grade 2 - low grade astrocytoma
- * Grade 3 - anaplastic astrocytoma
- * Grade 4 - Glioblastoma multiforme
What age groups do grade 1and2 astrocytomas tend to occur in? What age groups do grade 3and4 astrocytomas tend to occur in?
Low-grade astrocytomas (grade I and II) tend to be present in younger patients and have a better prognosis.
High-grade astrocytomas (grade III and IV) present in older patients, and the prognosis is dismal.
There are no known predisposing factors except rare familial syndromes and prior radiotherapy.
The astrocytic tumors are graded, using a three-tier system, into astrocytoma, anaplastic astrocytoma, and glioblastoma multiforme. Grading is based on pathologic features, such as endothelial proliferation, cellular pleomorphism, and mitoses
If there is necrosis, what type of astrocytoma is diagnosed? Where in the brain do grade 1 astrocytomas tend to occur?
If there is necrosis - this confirms the diagnosis of glioblastoma multiforme
Astrocytomas tend to occur in the cerebellum but can occur elsewhere in the brain
Describe grade 1 astrocytomas? Where do these pilocytic astrocytomas tend to occur? What is the treatment of option?
These are slow growing tumours with an unlikelihood of spread to other areas
Tend to occur in the cerebellum but can occurr in the optic nerve
Generally occur in children and young adults and unlikely to return after surgery
What might be the signs in a child with a pilcoytic astrocytoma?
Child may present with tip toe walking and vomiting (as well as other sins of raised ICP) - check for papilloedema
What are the different types of low grade astrocytoma? (Grade II)
This would be fibrillary, gemistocytic, protoplasmic
Where are the common locations of low grade astroctyomas? How are they likely to present?
Low grade astrocytoma - temporal lobe, posterior frontal or anterior parietal lobes
Seizures is the usual presentation of this tumour
Can have hemiparesis if affecting the motor cortex of frontal lobe also and headaches
Usually occurs in young
Pilocytic astrocytomas are unlikely to spread and usually remain benign Is this the same for low grade astroctyomas? What are fibrillay astrocytomas sometimes referred to as? What are poor prognostic factors?
Low grade astrocytomas is slow growing but will advance to stage 3 if left untreated
Fibrillary astrocytomas sometimes referred to as diffuse as it does not have well defined edges
- * Age >50
- * Focal deficit
- * Raised ICP and altered consciousness levels
What is usually the treatment of grade II astrocytomas?
Maximial safe resection of the tumour
With radio or chemo therapy if incomplete resection or patient is older
What is grade III astrocytoma known as? What is the median survival of this tumour?
This is a anaplastic astrocytoma
Mean survival is 2 years
Which astrocytomas grades are said to be malignant? What is grade IV astrocytoma known as? WHat is the mean survival?
Grades III & IV are said to be malignant
Grade IV - glioblastoma (glioblastoma multiforme GBM)
Mean survival is less than year
What is the most common cancerous primary brain tumour in adults? How does it spread?
The most common cancerous primary tumour is glioblastoma multiforme
It can spread via white matter tracking and CSF pathways resulting in the formatioon of multiple gliomas
What is the treatment for malignant astrocytomas?
Grade III/IV treatment - Maximal safe resection + chemoradiation
The surgery is cytoreductive (reduces number of cancerous cells) and followed up by chemoradiation
Not safe to drive post-op if seizure risk (all GBM) or if left with a significant &/or homonymous visual field defect. Patient must inform DVLA & you have a duty of care to the public if they do not.
What is the chemotherapy agent used in management of malignant tumours? Presence of what type of gene promoters make the addition of chemotherapy a main benefit? (what tumour biomarker)
The chemo agent used is temozolomide
It is an alkylating agent and the presence of a methylguanine methlytrnasferase (MGMT) methylated tumour make this treatment more likely to respond to temzolomide
Radiotherapy has a clear role in malignant astrocytomas post surgery Low grade astrocytomas - incomplete removal - malignant degeneration ( +/- surgery) When are they used in benign tumours? (Grade I) WHat are the side effects?
Only used if there is tumour recurrence (rare)
Drops IQ by 10, skin, hair and tired
Astrocytomas account for 60% of all primary brain tumours (2/3rds of which are high grade - grades III/IV (IV being most common)
WHat are the different treatments for each stage? WHere do grades I and II arise?
Grade I - arises in cerebellum usually, can arise in optic nerve or brainstem Surgery alone
Grade II - Arises in temporal, posterior frontal or anterior parietal lobes - usually surgery alone but + chemo/radiation if necessary
Grade III/IV - surgery + chemoradiation
Temozolomide used - better if methyguanine methyltransferase (MGMT) methylated tumour
What percentage of glial tumours do oligodendrogliomas account for?
They account for 20% of glial brain tumours
What lobes do oligodendrogliomas arise in? What age groups are they prevalent in? What is the common presentation?
They occur mainly in the frontal lobes
Prevalent in those aged 25-45
Commonly presents with seizures
Oligodendrogliomas must be differentiated from the more common astrocytoma. On CT scan of the tumour, what is uusally seen that differs it from astrocytomas?
CT demonstrates peripheral calcification of the tumour in the majority of cases
Often also have peritumoral haemorrhages and cysts
Oligodendriogliomas are usually low grade but can become high grade What is usually used for treatment?
Usually chemo + surgery for low grade tumours
For high grade - just chemotherapy
WHat is the triple combination of drugs given in chemotherapy for oligodendriogliomas? (PCV is a hint - remember the C is the molecular drug name)
This is procarbazine, lomustine and vincristine
What are the red flags for a presenting brain tumour? What does Tiptoeing, ataxia, vomiting with HA (headaches) in children make you think?
Headaches that make you wake +/- vomiting and new focal neurological deficit including seizures - red flags
Tiptoeing, ataxia, vomiting with headaches - this makes you think pilocytic astrcoytoma in a child (the tumour arises in the cerebellum hence the gait abnromalities)
What is the commonest extra-axial tumour? Where do the tumours arise from?
This is the meningioma
Arises from the arachnoid cap cells - these are the cells that absorb CSF fluid
Meningiomas Predominantly benign tumour of the meninges occurring at both cranial and spinal sites. They are occasionally atypical or malignant in nature.
WHat are the symptoms of presentation?
Headaches
Cranial nerve neuropathies if on skull base
Regional anatomical disturbance
What are two different risk factors for meningiomas?
Having had previous radiation to the head - these cause aggressive meningiomas or NF type II
Meningiomas are typically slow growing however can tend to increase in growth during pregnancy How are meningiomas classified?
* Classic (meningotheliomatous, fibrous, transitional)
* - Angioblastic
* - Atypical ( 2%)
* - Malignant (5%)
Malignant meningiomas are very aggressive and typically occur after childhood radiation Where do the aggressive types typically occur in the brain?
what age group do each of the brain tumours affect usually?
Typically occur in the midline
Meningiomas usually occur in adults
Low grade astrocytomas - children
High grade astrocytomas - adults
Oligodendriogliomas- 25-45yr olds
What are the names of the aggressive types of meningiomas? (Clue - CCRaP)
Clear cell
Chordoid
Rhabdoid
Papillary
MRI is the definitive diagnostic test for meningiomas Why is this? Remember, occur form the meninges
- This is because on MRI can see various things but the dural tail is very important- shows it arises from the dura mater
- Also on MRI - contrast-enhancing tumour, possibly with surrounding cerebral oedema
- CT - homogenous, densely enhancing -oedema - hyperostosis/ skull ‘blistering’
Angiography can sometimes be carried out to confirm a diagnosis of meningiomas Which artery is said to feed to the meningiomas tumour?
This would be the external carotid artery
What is the management of meningiomas? (small and large tumours)
Small - expectant management
Large - Surgical resection
What is the common symptoms of acoustic neuromas?
Also known as acoustic neuromas
Arise from the schwann cells of the myelin sheath (Schwann cells produce myelin in the PNS)
They are the most common tumour of the cerebellopontine angle affecting cranial nerves CN V, VII and VIII
Usually arrises form the myelin sheath of CN VIII
Associated with neurfibromatosis type II if young and bilateral tumours
What is the common symptoms of acoustic neuromas?
- * Hearing loss
- * Tinnitus
- * Facial weakness
- * Loss of sensation in face
- * Also balance disturbance
- * Can cause hydrocephalus if very large
Any asymmetrical hearing loss points to sensorineural Therefore what should be performed? What is the standard diagnostic test for acoustic neuromas?
Perform an audiogram - pure tone audiometry
Standard diagnostic testing is gadolinium-enhanced MRI head
Can use CT
What is the treatment of vestibular schwannomas?
If asymptomatic - observation = periodic neruo exam, hearing aids or periodic MRI to check for tumour growth
If the tumour is growing or causing too many symptoms - radiotherapy and surgery if the radiotherapy fails
What are the common problems post-op?
There is usuallly a facial nerve pasly
Reduced hearing/tinnitus
Check corneal reflex - if patient cant blink - ulcer development is likely
Abnormal eye movement
Hydrocephalus can also occur post radiation
What is the treatment used for hydrocephalus? What is the function of the pineal gland?
Treatment - ventriculoperitoneal shunt
Function of the pineal gland - produces melatonin which is important in regulating sleep patterns and circadian rythyms
Image shows pineal gland tumour
Tumours of the pineal gland are called pinealomas. These tumours are rare and 50% to 70% are germinomas that arise from sequestered embryonic germ cells. Histologically they are similar to testicular seminomas and ovarian dysgerminomas. WHat is the most common CNS germ cell tumour? WHat is this tumour sensitive to? What is raised in this tumour?
Most common CNS germ cell tumour - germinoma
It is radiosensitive
Usually PLAP (placentine alkaline phosphatase - remember this is raised in seminomas in testicles) is raised when this tumour is present
90% of germ cell tumours occur in patients under 20 For any midline brain tumour in a child, what should be measured in the serum? (pineal gland is midline -also it calcifies in old age)
Measure PLAP (placental alkaline phosphatase), HCG (human chorionic gonadotrophin), AFP(alfa feto protein)
What germ cell tumour is AFP, PLAP and HCG risen in? Pineal gland is most common location of intracranial germinomas
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P/C Bitemporal hemianopia, HA, endocrine abnormality Where is this tumour located?
Pituitary gland
What is the most common pituitary adenoma and second most common? Therefore what tests should be carried out first?
Prolactin is most common -prolactinoma
Growth hormone tumour is next most common
Measure prolactin
Measure IGF1 - insulin like growth factor 1
