Brain tumours Flashcards
what are the different categories of brain tumour?
Primary - gliomas (tumour of glial cells) or non-glial
Secondary - can stem from, lung (45%) , breast (25%) , colorectal (10%), testicular, renal cell, malignant melanoma (12%)
what is the epidemiology of brain tumours?
55% of brain tumours are malignant
9th most common cancer - Commonest cause men under 45 and women under 35
3% of all cancers
High grade gliomas most common primary brian tumour
Grade 1 pilocytic astrocytoma = common in children, benign, good prognosis
Medulloblastoma = common in children, curable potential, but grade 4 as highly malignant
Meningiomas - grade 1 but hard to remove
what is the aetiology of brain tumours?
Ionising radiation
5% genetic (family history of neurofibromatosis, tuberous sclerosis and von hippel-lindau disease
Immunosuppression (CNS lymphoma)
what is the pathophysiology of gliomas?
Diffuse gliomas:
Infiltrate diffusely into brain tissue (cannot remove all of tumour, only grade 2 and above)
Propensity to undergo progressive anaplasia
Astrocytoma IDH mutant - astrocytic differentiation, process bearing cells GFAP+, no deletion of 1p19q, grade 2, grade 3= mitoses, grade 4= microvascular proliferation and necrosis Oligodendroglioma IDH mutant - seizures, fried egg appearance, calcification on scan, grade 2, grade 3 = mitoses and avascular necrosis, always have 1p/19q deletion
Glioblastoma IDH wildtype - diffuse astrocytic tumour, grade 4, mitoses, necrosis and vascular proliferation
how are brain tumours graded?
Grade using morphology into four grades of malignancy, I most benign, IV most malignant
Grade I: Slow growing, non-malignant, and associated with long-term survival, complete cure possible (pilocytic astrocytoma)
Grade II: Have cytological atypia. These tumours are slow growing but recur as higher-grade tumours.
Grade III: Have anaplasia and mitotic activity. These tumours are malignant
Grade IV: Anaplasia, mitotic activity with microvascular proliferation, and/or necrosis. These tumours reproduce rapidly and are very aggressive malignant tumours
what are the key presentations of brain tumours?
Low grade – typically present with seizures (can be incidental finding).
High grade – rapidly progressive neurological deficit. Symptoms of raised intracranial pressure.
Headache - woken by headache, worse when lying down, first symptoms in 24%
Seizures - 21% presenting symptom
Focal neurological symptoms - Weakness, Sensory loss, Visual/speech disturbance, Ataxia
Other non-focal symptoms - Personality change/behaviour, Memory disturbance, Confusion
Papilloedema
Focal neurological deficit - hemiparesis, hemisensory loss, visual field defect, dysphagia
what are the first line and gold standard investigations for brain tumours?
Brian imaging - CT with contrast and MRI
Brain biopsy / surgery - MGMT methylation, IDH-1 mutation, Chromosome 1p19q loss (in oligodendroglial tumours)
how are brain tumours managed?
High grade glioma:
Steroids – reduce oedema , Surgery – biopsy or resection For tissue diagnosis, relief of raised ICP, prolongation of survival, Radiotherapy – mainstay of treatment Radical vs palliative, Chemotherapy – Temozolamide, PCV
Low grade glioma:
Surgery – early resection, Radiotherapy and early chemotherapy = improves overall survival time from 7.8 years to 13.3 years (NEJM study 2016)
what is the prognosis for brain tumours?
Brain cancer 5 year survival rate is 12%
HGG - 6 months no treatment /18 months with
LGG - Median survival 10 years
what are some common examples of brain tumours?
Pilocytic astrocytoma (grade I)
Subependymal giant cell astrocytoma (grade I)
Diffuse astrocytoma, IDH-mutant (grade II)
Oligodendroglioma, IDH-mutant and 1p/19q-codeleted (grade II)
Pleomorphic xanthoastrocytoma (grade II)
Anaplastic astrocytoma, IDH-mutant (grade III)
Anaplastic oligodendroglioma, IDH-mutant and 1p/19q-codeleted (grade III)
Anaplastic pleomorphic xanthoastrocytoma (grade III)
Glioblastoma, IDH-wildtype (grade IV)
Glioblastoma, IDH-mutant (grade IV)
Diffuse midline glioma, H3 K27M-mutant (grade IV)
