Intracranial tumours (summary)

Intracranial tumours comprise a heterogeneous group of tumours. In adult patients, the majority represent metastatic disease with a smaller proportion being primary brain tumours. Metastasis to the brain occurs from lung, breast, melanoma, renal cell and colorectal cancers.

Reference article

This is a summary article; read more in our article on intracranial tumours.

Summary

• epidemiology
  • incidence increases with age
  • equivocal gender distribution
  • risk factors
    • malignancy elsewhere
• presentation
  • headache
  • features of raised intracranial pressure
    • nausea & vomiting worse in the morning or positional
  • altered mental state
  • focal neurology may occur as the tumour grows
  • adult onset seizures
  • incidental finding
    • some tumours may not cause symptoms
    • patients may be imaged for another reason, e.g. trauma
• pathophysiology
  • heterogeneous group of tumours
    • metastases, e.g. lung, breast, renal
    • meningiomas
    • primary parenchymal tumours
    • pituitary or pineal tumours
    • cranial nerve schwannomas
  • tumours are graded using the WHO grade
• investigation
  • CT is often the first test performed to assess presenting symptoms
  • MRI may be used with symptoms of headaches or seizures
  • MRI is the investigation of choice to characterise the tumour
• treatment
  • parenchymal brain tumours generally have a poor prognosis
  • treatment should be in specialist centres
    • steroids may alleviate symptoms caused by oedema
    • anti-epileptic agents may help for those with seizures
    • a biopsy may be performed neurosurgically
    • some tumours may be removed, e.g. pituitary tumours
    • stereotactic radiotherapy can be used for small lesions

Role of imaging

• confirm intracranial abnormality and prioritise MRI
• characterise the tumour
• help to determine grade and make decision about biopsy
• follow up

Radiographic features

CT

CT is usually the first-line investigation in emergency presentations.

There can be a variety of appearances: both hypo and hyperdense in some situations, irregular or well defined, peripheral or deep or diffuse.

CT can be used to assess for complications such as bony involvement, hydrocephalus or mass effect. Contrast can also be used to further differentiate lesions.

MRI

MRI is the investigation of choice in investigating brain tumours.

MRI can identify early or small tumours missed on CT. Different sequences can define changes in brain parenchyma and meninges, evidence of infarct or haemorrhage related to tumours.

MRI can also be used to guide biopsies or resections, as well as in follow-up imaging.