CNS tumours Flashcards
define CNS tumours
Primary tumours arising from any of the brain tissue types.
aetiology of cns tumours
children - embryonic errors in development
adults - unknown
meningioma
Benign and most common primary CNS tumour.
fibrilliary astrocytoma
Most common form, usually in cerebrum.
Pilocytic astrocytoma:
Cystic, in cerebellum and brainstem.
Glioblastoma multiforme:
High-grade invasive tumour
Haemangioblastoma:
Vascular tumours, often in the cerebellum
Pituitary adenoma:
Benign. Space-occupying and endocrine effects.
Oligodendroglioma:
Ten percent of gliomas. Epileptogenic.
Medulloblastoma:
Invasive midline cerebellar tumour in children.
Ependymoma:
Benign, in spinal cord and fourth ventricle
Lymphoma:
In immunosuppressed patients, highly malignant
epidemiology of CNS tumours
Annual incidence of primary tumours 5–9 in 100 000.
2 peaks of incidence - children and elderly
sx of cns tumours
headache or vomiting from raised ICP
epilepsy - focal or generalised
focal neurological deficits - dysphagia, visual field defects, agnosia, hemianopia, hemiparesis, ataxia, personality change
unexplained weight loss, reduced appetite, and DVT can be non-specific signs of cancer
signs of CNS tumours
papilloedema/false localising signs - raised ICP
focal neurological deficits - visual field defects, dysphagia, agnosia, hemianopia, hemiparesis, ataxia, personality change
tumour in olfactory groove
anosmia, frontal lobe dysfunction
tumours in cavernous sinus
opthalmoplegia (CN3, 4, 6 palsy), V1 and V2 sensory loss
foster kennedy syndrome
= sphenoid wing meningioma compresses II nerve = ipsilateral optic atrophy and contralateral papilloedema
tumours in the pituitary fossa
bitemporal hemianopia (suprasellar expansion and optic chiasm compression), hypopituitarism or hypersecretion of specific hormones - acromegaly, hyperprolactinaemia, cushing’s
parinaud’s syndrome (pineal region)
impaired upgaze (superior midbrain lesion) or obstructive hydrocephalus (at level of 3rd ventricle)
tumour in para-sagittal region
spastic paraparesis (mimicking cord compression)
tumours in the cerebellopontine angle
unilateral deafness, facial weakness, unilateral ataxia and hemifacial sensory impairment
Ix for CNS tumours
CT head - usual initial exam
MRI brain in progressive, sub-acute loss of central neurological function.
- higher sensitivity
- diffuse weighted imaging and MR spectroscopy can be helpful in characterising lesion w/o biopsy
- functional MRI may be necessary if lesion is located in dominant hemisphere for surgical planning
CXR or CT thorax, abdo and pelvis - determine if lesion is primary or secondary
blood
- CRP, ESR
- HIV screen
- toxoplasma serology
brain biopsy - type and grading - degree of differentiation of tumour
LP 0 relative contraindication if evidence of raised ICP - may cause coning (herniation)
