Pathology of Brain Tumours Flashcards
What are the thick tough fibrous sheets that keep the brain in place?
Falx cerebri
Tentorium cerebelli
Where does the spinal cord open through the skull?
Through the foramen magnum
Causes of raised ICP
Localised lesions - haemorrhage (haematoma if localised) - tumour - abscess Generalized pathology - e.g. oedema post trauma
What does SOL stand for?
Space occupying lesion
Examples of SOL in the head
Tumours
Bleeding (haematoma)
Abscess
Effects of intracranial SOLs
Amount of tissue increases
Raises ICP
Causes internal shift (herniation) between intracranial spaces
- right left or left right
- cerebrum moves inferiorly over edge of tentorium (uncal herniation)
Cerebellum moves inferiorly into foramen magnum (coning)
What does swelling and shift of brain tissue lead to?
Localised ischaemia
Presentation of a squeeze on the cortex and brainstem
Morning headaches
Sickness
Presentation of a squeeze on the optic nerve
Papilloedema (on fundoscopy)
Presentation of a rising ICP
Pupillary dilation - squeeze and stretch on CN 3
Falling GCS - squeeze on cortex and brainstem
Brain stem death - squeezing downwards of cerebellum into foramen magnum with crushing of brainstem
What does a subfalcine herniation lead to?
A midline shift - brain pushed away from the tumour
What type of herniation causes brainstem death?
Cerebellar Tonsillar Herniation
Types of intracranial tumours
CNS - primary - secondary (metastatic) Other - originating from outside brain and spinal cord e.g. meningioma
Examples of primary intracranial tumours
Gliomas Medulloblastoma Meningioma Schwannoma Neurofibroma Adenoma Lymphoma Haemangioblastoma
Types of gliomas
Glioblastoma
Astrocytoma
Oligodendroglioma
Ependyoma
What do gliomas originate from?
Glial cells
What do medulloblastomas originate from?
Embryonic neural cells
What do meningiomas originate from?
Arachnoidal cells
What do schwannomas and neurofibromas originate from?
Nerve sheath cells
What do adenomas arise from?
Pituitary gland
What do lymphomas arise from?
Lymphoid cells
What do hemangioblastomas arise from?
Capillary vessels
What cancers commonly metastasize to the brain?
Breast Lung Kidney Colon Melanoma
Are glial cell tumours (gliomas) malignant or benign?
Malignant
What are embryonic neural cell tumours (medulloblastomas)?
Childhood malignant tumours
Where are the majority of CNS tumours found in an adult?
Above the tentorium
Where are the majority of CNS tumours found in a child?
Below the tentorium
Features of gliomas
Resemble cells of glial differentiation
Diffuse edges
Not encapsulated
Malignant but do NOT metastasize outside of the CNS
Examples of gliomas resembling cells of glial differentiation
Astrocytes (astrocytoma)
Oligodendrocytes (oligodendroglioma)
Ependymal cells (ependymoma)
Main type of glioma
Astrocytoma
What is another name for astrocytoma?
Glioblastoma
Features of meningiomas
Benign Does not metastasise Can be locally aggressive and invade the skull Slow growing Often resectable
What is a pituitary adenoma?
Benign tumour of the pituitary in the pituitary fossa
How does pituitary adenoma grow?
Superiorly
Impinge on the optic chiasma
Features of a CNS Lymphoma
High grade neoplasm
Usually diffuse large B-cell lymphoma
Often deep and central site in the brain (difficult to biopsy)
Where do people most often get hemangioblastoma?
Cerebellum
What is a schwannoma around the 8th CN called?
Acoustic neuroma
Presentation of acoustic neuroma
Unilateral deafness
How are brain tumours classified?
Tissue of origin
Location
Primary or secondary (metastatic)
Grading
What is the second most common brain tumour after glioma?
Meningioma
Who gets meningiomas?
40 - 70 y/o
F > M
Pathology of meningioma
Arise from arachnoidal cap cell type from arachnoid membrane
Usually non invasive
What are meningiomas associated with?
NF-2
Where can meningiomas be located?
Parasagittal region
Sphenoid wing
Parasellar region
Presentation of meningioma
Asymptomatic
Symptomatic
- focal or generalised seizure or gradually worsening neurological deficit
Investigations of meningioma
CT
MRI
What does meningioma look like on CT?
Isodense or hypodense
Homogenous extra-axial mass with smooth or lobulated, clearly demarcated contours which enhance homogenously and densely with contrast
Frequently have areas of calcification and produce hyperostosis of adjacent bone
What does meningioma look like on MRI?
Isotense with grey matter on T1 images
Enhance with contrast - often with enhancing dural trail extending from the tumour attachment
Spectrum of astrocytomas ranges from what to what?
Benign to malignant
What is an astrocytoma a type of?
Glioma
What is a benign type of astrocytoma called?
Low grade pilocytic astrocytoma
What is a type of malignant astrocytoma called?
High grade astrocytoma / Glioblastoma multiforme
Who gets diffuse low grade astrocytomas?
Young adults
Locations of diffuse low grade astrocytomas
Widely infiltrate surrounding tissue
- Frontal region
- subcortical white matter
Presentation of diffuse low grade astrocytomas
Seizures
Headache
Slowly progressive neurological deficits
What is seen on CT with a diffuse low grade astrocytoma?
Well circumscribed
Non enhancing
Hypodense
Isodense lesion
What is the most common type of primary brain tumour in adults?
High grade astrocytoma / glioblastoma
Who gets glioblastomas?
40 - 60 y/os
M > F
How may a glioblastoma arise?
De novo
From a low grade glioma
Pathology of glioblastoma
Tumour infiltrates along white matter tract and can cross the corpus callosum
Can look like a butterfly lesion
Prognosis of glioblastoma
Very malignant
Poor prognosis
Location of glioblastoma
Frontal and temporal lobes
Basal ganglia
Presentation of glioblastoma
Seizures
Headache
Slowly progressive neurological deficits
Mean onset of an oligodendroglioma
40 y/o
What do oligodendrogliomas arise from?
Myelin
Features of oligodendroglioma
Characteristic “fried egg” appearance
Slow growing
Location of oligodendroglioma
Superficially in frontal lobes
Presentation of oligodendroglioma
Seizures most common
Headache
Slowly progressive neurological deficits
What does an oligodendroglIoma look like on CT?
Well circumscribed, hypodense lesions with heavy calcification
Cystic degeneration is common but haemorrhage and oedema are uncommon
What does CNS lymphoma cause?
Increased ICP
Brain destruction
What cancers commonly spread to the brain?
Melanoma
Renal cell
Choriocarcinoma
A schwannoma is unilateral in what % of cases?
90%
When are bilateral lesions seen with schwannomas?
Almost exclusively in NF2
What can pineal germinoma cause and why?
Obstructive hydocephalus
Due to aqueduct stenosis
What can a brainstem glioma cause?
Locked in syndrome
What is the only known risk factor for a brainstem glioma?
NF1
Who is low grade pilocytic astrocytomas mostly common in?
Young children
What is a hemangioblastoma characterised by?
Abundant capillary blood vessels
What is a hemangioblastoma assosiated with?
Retinal lesions
What do intra-axial gliomas originate from?
Glial cells
Types of gliomas
Astrocytoma (grade I and III) Anaplastic astrocytoma (III) Glioblastoma multiforme (IV)
Survival of glioblastoma multiforme
8 - 10 months
Where do ependymomas arise from?
Lining of the ventricle
What is a ependymoma?
Benign tumour which causes obstruction of CSF
Where is ependymoma most commonly found?
4th ventricle
Median age of diagnosis of ependymoma
5 y/o
What is the second commonest tumour in children?
Medulloblastoma
What is a medulloblastoma highly sensitive to?
Radiotherapy
Who is CNS lymphoma common in?
Immunocompromised patients e.g. transplant, AIDs
Survival of CNS lymphoma
1 - 4 years
Treatment of CNS lymphoma
Chemotherapy
Radiation/decadron
Where do extra-axial tumours arise from?
Supporting structures on the CNS
Examples of extra-axial tumourd
Meningioma Metastatic Acoustic neuroma (schwannoma) Pituitary adenoma Neurofibroma
Examples of intra-axial tumours
Gliomas Oligodendroglioma Ependymomas Medulloblastoma CNS lymphoma
Features of meningioma
Slow growing
Attached to meninges
Usually benign
What usually causes mets to cause a extraaxial tumour?
Lung
Breast
Kidney
GI
Where do you find an acoustic neuroma?
CN VIII
Is an acoustic neuroma benign or malignant?
Benign
How is a pituitary adenoma classified?
Hormone secretion
Location
Types of prolactin secreting pituitary adenomas
Microadeoma
Macroadenoma
What level of serum prolactin indicates a prolactin secreting tumour?
> 500Mu/L
Presentation of a microprolactinoma
Hyperprolactinaemia Gallactorrhoea Amenorrhoea Impotence Infertility in males
Presentation of a pituitary adenoma
May cause hyperprolactinaemia
May cause growth hormone deficiency
May present with endocrine abnormalities
May present with bilateral temporal heminaopia
Presentation of growth hormone deficiency in childhood
Dwarfism
Slow / absent growth
Absent / delayed sexual development
Cephalofacial disproportion
Presentation of adulthood GH deficiency
Increased body fat Decreased muscle mass Decreased bone density - increased risk of fractures - impaired glucose tolerance
Inheritance of neurofibroma
Autosomal dominant
What are neurofibromas attached to?
Nerve
Are neurofibromas benign or malignant?
Benign
When do neurofibromas occur?
Childhood / early adolescence
Treatment of neurofibroma
Surgery
Radiation
What does the presentation of a brain tumour depend on?
Location
Size
Type
Presentation of brain tumours
Cerebral oedema Increased ICP Focal neurological deficits Obstruction of flow of CSF Pituitary dysfunction Papilloedema
Presentation of cerebral tumours
Headache Vomiting unrelated to food intake Changes in visual fields and acuity Hemiparesis or hemiplegia Hypokinesia Decreased tactile discrimination Seizures Changes in personality or behaviour
Presentation of brainstem tumours
Hearing loss (acoustic neuroma) Facial pain and weakness Dysphagia Decreased gag reflex Nystagmus Hoarseness Ataxia Dysarthria
Definition of ataxia
Loss of muscle contraction
Definition of dysarthria
Speech muscle disorder
What do cerebellar tumours cause?
Disturbances in coordination and equilibrium
What do pituitary tumours cause?
Endocrine dysfunction
Visual deficits
Headache
Presentation of frontal lobe tumours
Inappropriate behaviour Personality changes Inability to concentrate Impaired judgement Memory loss Headache Expressive aphasia Motor dysfunctions
Presentation of parietal lobe tumours
Sensory deficits
- paraesthesia
- loss of 2 pt discrimination
- visual field defects
Presentation of temporal lobe tumours
Psychomotor seizures Temporal lobe judgement Behaviour Hallucinations Visceral symptoms No convulsions Loss of consciousness
Presentation of occipital lobe tumours
Visual disturbances
Investigations of brain tumour
CT with/without contrast MRI with/without contrast Plain films Myelography PET scan LP/CSF analysis
What investigation is mostly used widely for the investigation /diagnosis of brain tumours?
CT
What is the most preferred investigation for the follow up of most brain tumours?
MRI
Treatment of brain tumours
Steriods Surgical treatment - resection - biopsy - craniotomy - sterotaxis surgery - transsphenoidal - endoscopic
Post op complications of brain surgery
Increased ICP Haematoma Hypovolaemic shock Atelectasis Pulmonary oedema Meningitis Fluid and electrolyte imbalances (ADH) Wound infection Seizures CF leak Oedema
What type of cells are sensitive to radiation?
Cells that rapidly divide (e.g. brain tumours) and normal tissue too
Types of radiation
External beam radiation
Stereotactic radiosurgery (gamma, inax, cyberknife)
Interstitial brachytherapy
Considerations that need to be taken with radiotherapy
Skin burns and reddened skin from beam of radiation
Corticosteriods are given during radiation to control cerebral oedema
Radiation necrosis may occur after treatments are completed; may need to be surgically removed
What does chemotherapy do?
Slows cell growth
How are chemotherapy drugs administered?
PO
IV
Intrathecal routes
Examples of chemotherapy drugs
Temozolomide (temodar) CCNU BCNU Cisplatin Etoposide
Acute side effects of chemotherapy
Oral mucositis Bone marrow suppression Fatigue Hair loss Nausea/vomiting Anxiety Peripheral neuropathy
What is used to treat N + V?
Anti emetics
What % of cancer patients develop brain metastases?
10 - 15%
Another name for vestibular schwannoma
Acoustic neuroma
Classical presentation of acoustic neuroma
Vertigo
Hearing loss
Tinnitus
Absent corneal reflex
What CNs can be affected in acoustic neuroma?
CN VIII
CN V
CN VII
Presentation of CN VIII if affected in acoustic neuroma?
Vertigo
Unilateral sensorineural hearing loss
Unilateral tinnitus
Presentation of CN V if affected in acoustic neuroma
Absent corneal reflex
Presentation of CN VII if affected in acoustic neuroma
Facial palsy
When are bilateral acoustic neuromas seen?
NF2
Treatment of acoustic neuromas
Observed initially as benign and slow growing
Radiotherapy
Surgery
Investigation of acoustic neuroma
MRI of cerebellopontine angle
Audiometry
What is the most common primary cancer responsible for brain metastases?
Lung