Brain tumour Flashcards
Astrocytic tumour classifications
I: pilocytic astrocytoma
II: astrocytoma
III anaplastic astrocytoma
IV: glioblastoma
Oligodendricytic tumour classifications
II: oligodendroglioma
anaplastic oligodendroglioma
Classes of brain tumours
I: in-situ/localized
II: diffuse
III: undefied
IV: malignant
Neuron tumour classifications
I: gangliocytoma
II: neurocytoma
Ependymal tumour classifications
I: subependymoma
II; ependymoma
III: anaplastic ependymoma
Meningeal tumour classifications
I: meningioma
II: atypical meningioma
III: anaplastic meningioma
Neurononal stem cell tumour classification
IV: neuroblastoma (PNET) - named by location Medulloblastoma Neuroblastoma Retinoblastoma Pineoblastoma
Mixed brain tumour classification
I: ganglioglioma
II: mixed oligoastrocytoma
III: anaplastic oligoastrocytoma
PSNS tumour classifications
I:Schwannoma/neurofibroma
IV: malignant peripheral nerve sheath tumour
General principles of brain tumours
1/2 are “benign” but mass effect
cure rate for malignant brain tumours much lower than other cancers
lifetime risk: 1/200
leading cause of cancer deaths in children/teenagers
2nd leading cause of cancer deaths in males 20s-40s
40% primary CNS tumours: gliomas
80% of malignant CNS tumours: gliomas
CNS tumour etiology
majority are unknown Irradiation --> meningoma, glioma, nerve sheath tumours Genetic Immunosuppression: CNS lymphoma Experimental: SV40 Occupation: some risk Trauma, diet- no convincing data
CNS tumour risk factors
Sex: gliomas Men. women
Meningiomas: women > men
Association with breast cancer and meningioma
Cell phone: of concern
Clinical features of CNS tumours
epilepsy headache raised ICP focal neurologic deficit short history: more aggressive
Intracranial CNS tumour distribution
adults: 70% supratentorial, 30% infra
children: 30% supra, 70% infra
CNS tumours common among adults
glioblastoma metastasis malignant astrocytoma meningioma pilocytic Schwannoma
CNS tumours common among children
medulloblastoma astrocytoma ependymoma craniopharyngioma glioblastoma
Glioblastoma 5 year survival
3-4%
Anaplastic astrocytoma 5 year survival
30%
Oligodendroglioma 5 year survival
60%
Ependymoma 5 year survival
60%
Medulloblastoma 5 year survival
60%
Pilocytic astrocytoma 5 year survival
> 80%
Meningioma 5 year survival
70-95%
Pilocytic astrocytoma features
predominantly in childhood usually cerebellum, optic tract, hypothalamus others: more guarded prognosis often cystic (esp cerebellum) potentially curable by complete excision
Pilocytic astrocytoma genetics
most common: gains on 7q34
Often associated with duplications of BRAF, HIPK2 genes
- not associated with clinical outcome for cerebellar tumours
- predict better clinical outcome for low grade gliomas in pediatric patients
- activation of MAP kinase signalling pathway
DIffuse gliomas
40% of all primary CNS tumours
78% of malignant CNS tumours
>80% of high grade gliomas
Tumour suppressor genes involved in CNS tumours
p53
Rb: retinoblastoma
p16
p19
Oncogenes involved in CNS tumours
Epidermal growth factor receptor: GBM
pltaelet-derived growth receptor alpha: low grade astrocytoma
CNS tumour metastasis
Lung (50%) Breast (15%) Skin (melanoma - 10%) GI GU 80-90% are in the brain, 10-20% spinal
CNS effects of cancer treatment
Radiotherapy: encephalopathy delayed myelopathy hypothalamic/pituitary disturbance oncogenesis
Chemo:
encephalopathy/myelopathy
cerebellar
