neuro-oncology Flashcards
cancer
tumour
Cancer = a group of diseases caused when cells divide and grow in an uncontrolled manner
Tumour = a mass of cancerous cells
Intracranial tumours are classified based on pathology and
site and these dictate the clinical presentation
neuroepithelial
Astrocytoma Oligodendroglioma Ependymoma Glioblastoma muliforme (GBM) Medulloblastoma
meninges
meningioma
nerve sheath cells
neuroma / schwannoma
neurofibroma
blood vessels
Haemangioblastoma
cerebellar tumours
infratentorial
supratentorial
Infratentorial brain tumours are more common in children (medulloblastoma, cerebellar astrocytoma)
Supratentorial = 85% adult brain tumours (most common astrocytoma, meningioma and metastases)
primary secondary brain tumour intrinsic extrinsic
Primary Brain Tumour: Mass of abnormal cells that arises from within the brain parenchyma
Secondary Brain Tumour / Brain Metastasis: Spread of cancer cells from a primary tumour outside the brain
Intrinsic: Tumour cells within the brain tissue
Extrinsic : Tumour cells located outside the brain tissue
Histology: composition of cells and their organization
Mass Effect: compression caused by increased intracranial pressure from a space-occupying lesion
Space Occupying Lesion (SOL): Describes a mass of unknown
histology on MRI
clinical features
Insidious, gradual onset
Depends on site and degree of malignancy
Raised intracranial pressure – headache, papilloedema
Mass effect with brain shift – vomiting, deteriorating consciousness, pupillary dilatation
Epilepsy in 30% - initial or later
Neurological deficits depend on site of tumour, usually not the first presenting symptom or sign
brain tumour work up
Imaging: CT / MRI / MR or CT angiography
Surgical intervention: biopsy ± debulking / decompression / excision
Histopathology: frozen section (in surgery) and histology of biopsy (5- 7 days)Medical or radio- oncology management depending on pathological classification
brain tumour management
steroid therapy Reduce mass effect and oedema
Do not affect
tumour growth
Dexamethasone
surgery Craniotomy
Subsequent procedure depends on findings
May be awake if tumour approaches “eloquent brain”
radiotherapy Destruction of cancer cells with XRay beams
Stereotactic
Gamma knife
chemotherapy Limited value in “gliomas”
Used in lymphomas
Metastases may
respond
astrocytoma and glioblastoma multiforme
Most common (40% of all intracranial tumours in adults)
Peak incidence 40-60y, M:F 2:1
Site: equal incidence in frontal, temporal, parietal and thalamic regions, rare in occipital lobe
Graded 1 to 4
Classification depends on biopsy obtained at surgery
meningioma
Arises from the arachnoid granulations Tends to compress rather than invade tissue Generally low grade Can also occur in the skull base, orbit and spinal canal
nerve sheath cells
Schwannoma
Non-invasive / “benign”
Slow growing (2mm / y, but may not grow)
Usually occur in middle age 40-50 years
More frequent in females
Most common location: vestibular portion of CNVIII (vestibular schwannoma) and cerebellopontine angle (CP angle)
Management depends on disability from compression of surrounding structures
Haemangioblastoma
Vascular origin
Generally low grade lesion
Mainly occurs in the middle aged
Most common primary brain tumour of the cerebellum in adults
70% association with presence of a cyst
Characteristic of Von Hippel Lindau Syndrome
metastatic lesions
Any malignant tumour can metastasise to the brain
Highest frequency is malignant melanoma (66%)
Most common primary site is bronchus and the breast
25% of patients with this primary diagnosis develop brain mets
50% have multiple metastases
Intracranial sites: ¾ hemispheres, ¼ cerebellum
Characteristics: surrounding oedema, well defined tumour margins, necrotic areas that may break down to form cystic cavities
Mets are the commonest tumours of the cerebellar hemisphere
