CNS tumours

Question 1

definition

Answer 1

primary tumours arising from any of the brain tissue types

Question 2

symptoms

Answer 2

• Headache or vomiting (raised intracranial pressure)
• epilepsy (focal or generalized)
• focal neurological deficits (dysphagia, hemiparesis, ataxia
• visual field defects
• cognitive impairment)
• personality change.

Question 3

examination/signs

Answer 3

• Papilloedema/false localizing signs (raised intracranial pressure).
• Focal neurological deficits (visual field defects, dysphasia, agnosia, hemianopia, hemiparesis,
  ataxia, personality change)

Question 4

types of CNS tumours

Answer 4

. 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.

** meningiomas and basal cell carcinomas don’t usually metastasise. vestibular schwannomas are usually benign.

Question 5

most common brain mets

Answer 5

• melanoma of the scalp

- SCC of the scalp

Question 6

investigations

Answer 6

1st investigation:
CT-head: Usual initial investigation.

MRI-brain: Higher sensitivity. Diffusion-weighted-imaging and MR spectroscopy can be helpful in characterizing lesion without biopsy.
Functional MRI may be necessary if the lesion is located in dominant hemisphere for surgical planning.
Chest X-ray or CT (thorax, abdomen, pelvis): To determine if the lesion is secondary or primary.
Blood: CRP, ESR, consider HIV screen, toxoplasma serology.
Brain biopsy: Type and grading (degree of differentiation of tumour).
Lumbar puncture: Lumbar puncture is a relative contraindication if there is evidence of raised intracranial pressure, may cause coning (herniation)!!