CNS tumours

Question 1

define CNS tumours

Answer 1

Primary tumours arising from any of the brain tissue types.

Question 2

aetiology of cns tumours

Answer 2

children - embryonic errors in development

adults - unknown

Question 3

meningioma

Answer 3

Benign and most common primary CNS tumour.

Question 4

fibrilliary astrocytoma

Answer 4

Most common form, usually in cerebrum.

Question 5

Pilocytic astrocytoma:

Answer 5

Cystic, in cerebellum and brainstem.

Question 6

Glioblastoma multiforme:

Answer 6

High-grade invasive tumour

Question 7

Haemangioblastoma:

Answer 7

Vascular tumours, often in the cerebellum

Question 8

Pituitary adenoma:

Answer 8

Benign. Space-occupying and endocrine effects.

Question 9

Oligodendroglioma:

Answer 9

Ten percent of gliomas. Epileptogenic.

Question 10

Medulloblastoma:

Answer 10

Invasive midline cerebellar tumour in children.

Question 11

Ependymoma:

Answer 11

Benign, in spinal cord and fourth ventricle

Question 12

Lymphoma:

Answer 12

In immunosuppressed patients, highly malignant

Question 13

epidemiology of CNS tumours

Answer 13

Annual incidence of primary tumours 5–9 in 100 000.

2 peaks of incidence - children and elderly

Question 14

sx of cns tumours

Answer 14

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

Question 15

signs of CNS tumours

Answer 15

papilloedema/false localising signs - raised ICP

focal neurological deficits - visual field defects, dysphagia, agnosia, hemianopia, hemiparesis, ataxia, personality change

Question 16

tumour in olfactory groove

Answer 16

anosmia, frontal lobe dysfunction

Question 17

tumours in cavernous sinus

Answer 17

opthalmoplegia (CN3, 4, 6 palsy), V1 and V2 sensory loss

Question 18

foster kennedy syndrome

Answer 18

= sphenoid wing meningioma compresses II nerve = ipsilateral optic atrophy and contralateral papilloedema

Question 19

tumours in the pituitary fossa

Answer 19

bitemporal hemianopia (suprasellar expansion and optic chiasm compression), hypopituitarism or hypersecretion of specific hormones - acromegaly, hyperprolactinaemia, cushing’s

Question 20

parinaud’s syndrome (pineal region)

Answer 20

impaired upgaze (superior midbrain lesion) or obstructive hydrocephalus (at level of 3rd ventricle)

Question 21

tumour in para-sagittal region

Answer 21

spastic paraparesis (mimicking cord compression)

Question 22

tumours in the cerebellopontine angle

Answer 22

unilateral deafness, facial weakness, unilateral ataxia and hemifacial sensory impairment

Question 23

Ix for CNS tumours

Answer 23

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)