Neurosurgery notes/Tumours/Tumour general/CNS tumour summary

CNS tumour summary

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Tumour general

Numbers

Brain tumours

Adults
Commonest Primary Brain Tumors by Subtype
%
Meningioma
36%
Pituitary tumors
15.5%
Glioblastoma
15.1%
Nerve sheath tumors
8.1%
Diffuse astrocytoma
2.3%
Primary CNS lymphoma
2%
Ependymal
1.9%
Anaplastic astrocytoma
1.70%
Pilocytic astrocytoma
1.4%
Neuronal and neuronal mixed
1.2%
Oligodendroglioma
1.1%
Oligoastrocytoma
0.9%
Craniopharyngioma
0.8%
Anaplastic oligodendroglioma
0.5%
Commonest Primary Brain Tumours by WHO Group
%
Meninges
37.6%
Neuroepithelial tissue
29.9%
Sellar region
16.3%
Cranial and spinal nerves
8.1%
Unclassified
5.6%
Lymphoma and hematopoietic
2.10%
Germ cell tumors and cysts
0.4%
Paediatric
Brain
Pilocytic astrocytoma
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Medulloblastoma
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Craniopharyngioma
ㅤ
Ependymoma
ㅤ
Post fossa
%
Pilocytic astrocytoma
30
Medulloblastoma
30
Ependymoma
30
Diffuse brainstem
10

Spine tumours

Adults
Intramedullary (1/3 intradural)
%
Ependymoma
60%
Astrocytoma
35%
Haemangioblastoma
5%
 
IDEM (2/3 intradural)
%
Meningioma
50%
Nerve sheath tumour
50%
Extradural
ㅤ
Spinal mets
90%
Primary bone tumours
ㅤ
Paediatrics
Intramedullary (1/2 intradural)
%
Astrocytoma
82%
Ganglioglioma
35%
Ependymoma
12%
Haemangioblastoma
2%
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IDEM (1/2 intradural)
%
Nerve sheath tumours
ㅤ
Extradural
%
Neuroblastoma
26%
Ewing’s sarcoma
1%
Rhabdomyosarcoma
3%
Osteogenic sarcoma
2%
Lymphoma
8%
Germ cell tumours
5%
Leukemia
3%
Wilms’s tumor
2%

Metastatic tumour

Adults
Brain
%
Lung cancer (Adeno & small cell)
44
Breast cancer
10
Renal cell carcinoma
7
Colorectal cancer
6
Melanoma
3
Undetermined
10
Spine
%
Breast
17
Prostate
15
Lung
10
Renal
7
Undetermined
10
Paediatrics
Brain
%
Neuroblastoma
4.4
Osteosarcoma
1.9
Rhabdomyosarcoma
6.5
Ewing sarcoma
3.3
Melanoma
3.6
Germ cell
13.5
Wilms
1.3
 

Paediatric age ranges

  • New-born (ages 0–4 weeks)
  • Infant (ages 4 weeks – 1 year)
  • Childhood
    • Toddler(ages 1–2 years)
    • Pre-schooler (ages 3–5 years)
    • School-aged child (ages 6–12 years)
  • Adolescent (ages 13–19).

Sign and symptoms

Supra tentorial tumours

Focal deficits (Weakness and Dysphasia) -68%
  • Due to
    • Tumour invasion → Destruction of brain parenchyma
    • Tumour mass/peritumoral oedema/haemorrhage → Compression of brain parenchyma
    • Cranial nerve compression
  • Location
    • Frontal lobe:
      • Often non-lateralizing
      • Symptoms:
        • Abulia,
        • Dementia,
        • Personality changes.
        • Apraxia,
        • Hemiparesis or dysphasia (with dominant hemisphere involvement)
    • Temporal lobe:
      • Auditory or olfactory hallucinations,
      • Déja vu,
      • Memory impairment.
      • Contralateral superior quadrantanopsia may be detected on visual field testing
    • Parietal lobe:
      • Contralateral motor or sensory impairment,
      • Homonymous hemianopsia.
      • Agnosias (with dominant hemisphere involvement)
      • Apraxias
    • Occipital lobe:
      • Contralateral visual field deficits,
      • Alexia (especially with corpus callosum involvement with infiltrating tumors)
    • Posterior fossa:
      • Cranial nerve deficits,
      • Ataxia (truncal or appendicular)
Headaches -54%
  • Classically described as being worse in the morning (this might not be true)
    • Possibly due to hypoventilation during sleep
  • H/A
    • 77% of brain tumor patients were similar to tension H/A, and in
    • 9% were migraine-like.
    • 8% showed the “classic” brain tumor H/A (worst in AM)
      • Two–thirds of these patients had increased ICP.
  • Exacerbated by
    • Coughing,
    • Straining, or
    • Bending forward (in 30%)(placing head in dependent position).
  • Associated with
    • Nausea and vomiting in 40%,
      • May be temporarily relieved by vomiting (possibly due to hyperventilation during vomiting).
  • Aetiologies
    • Increased ICP: which may be due to
      • Tumour mass effect
      • Hydrocephalus (obstructive or communicating)
      • Mass effect from associated oedema
      • Mass effect from associated haemorrhage
    • Invasion or compression of pain sensitive structures:
      • Dura
      • Blood vessels
      • Periosteum
    • Secondary to difficulty with vision
      • Diplopia due to dysfunction of nerves controlling extra-ocular muscles
        • Direct compression of III, IV, or VI
        • Abducens palsy from increased ICP,
        • Internuclear ophthalmoplegia due to brainstem invasion/compression
      • Difficulty focusing: due to optic nerve dysfunction from invasion/compression
    • Extreme hypertension resulting from increased ICP (part of Cushing’s triad)
    • Psychogenic: due to stress from loss of functional capacity (e.g. deteriorating job performance)
Seizure-26% (lecture says it 80%)
  • Must rule out tumour if it is an idiopathic first time seizure in a patient > 20 yrs, even if it is negative must do a repeat MRI a later date
  • Due to cortical irritation by tumour
    • Focal → generalized
  • Rare in post fossa or pituitary tumors
  • Common in
    • DNET
    • Gangliomas
      • Gangliogliomas
      • Gangliocytomas
Change in mental status
  • Depression
  • Lethargy
  • Apathy
  • Confusion
  • Cognitive changes in 80%
Tumour TIA
  • Due to
    • Occlusion of vessel by tumour cells
    • Haemorrhage into the tumour
    • Focal seizure → post ictal
Pituitary tumours
  • Endocrine disturbances
  • Pituitary apoplexy
  • CSF leak

Infratentorial tumours

  • Seizures are rare
  • HCP
    • Due to raised ICP
    • Presents as
      • H/A
      • N/V
      • Papilledema
      • Ataxia
      • Vertigo
      • Diplopia:
        • 6th nerve palsy due to stretching of the nerve when the brain stem gets pushed down.
        • The nerve is tethered to the pons and the dorrello's canal
    • HCP treatment in tumour
      • Some authors advocate initial placement of VP shunt or EVD prior to definitive surgery (waiting ≈ 2 wks before surgery) because of possibly lower operative mortality.
        • Theoretical risks of shunting:
          • Placing a shunt is generally a lifelong commitment, whereas not all patients with hydrocephalus from a p-fossa tumor will require a shunt
          • Possible seeding of the peritoneum with malignant tumor cells e.g. with medulloblastoma.
            • Consider placement of tumor filter
              • May not be justified given the high rate of filter occlusion and the low rate of “shunt metastases”
          • Some shunts may become infected prior to the definitive surgery
          • Definitive treatment is delayed, and the total number of hospital days may be increased
          • Upward transtentorial herniation may occur if there is excessively rapid CSF drainage
            • Can be reduced by only opening the shunt or after opening of the supratentorial dura
        • Post-op, EVD set at a low height (10cm) for 24 hours → raised slowly next 72 hrs then removed.
  • S/S indicative of mass effect in various locations within the p-fossa
    • Lesion in cerebellar hemisphere
      • Ataxia of extremities
      • Dysmetria
      • Intention tremor
    • Lesion of cerebellar vermis
      • Broad based gait
      • Truncal ataxia
        • Titubation: nodding of the head an essential tremor
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    • Lesion in the Brainstem
      • Suspected when nystagmus is present rotatory or vertical
      • See the 4 rules of brain stem anatomy to figure out where the lesion is