Intracranial tumors (summary)

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This is a basic article for medical students and other non-radiologists

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

Reference article

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

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 tumor grows
    • adult-onset seizures
    • incidental finding
      • some tumors may not cause symptoms
      • patients may be imaged for another reason, e.g. trauma
  • pathophysiology
    • heterogeneous group of tumors
      • metastases, e.g. lung, breast, renal
      • meningiomas
      • primary parenchymal tumors
      • pituitary or pineal tumors
      • cranial nerve schwannomas
    • tumors 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 characterize the tumor
  • treatment
    • parenchymal brain tumors generally have a poor prognosis
    • treatment should be in specialist centers
      • steroids may alleviate symptoms caused by edema
      • anti-epileptic agents may help for those with seizures
      • a biopsy may be performed neurosurgically
      • some tumors may be removed, e.g. pituitary tumors
      • stereotactic radiotherapy can be used for small lesions

Imaging

  • role of imaging
    • confirm intracranial abnormality and prioritise MRI
    • tumor characterization
    • help to determine the grade, and make a decision about biopsy
    • follow up
  • radiographic features
    • CT
      • often the first line test
      • variety of appearances depending on the tumor
      • hypo- or hyperdense, irregular, well-defined, peripheral or deep
      • useful to determine edema and mass effect
      • contrast may make lesions more conspicuous
      • CT is especially helpful for determining bony involvement
    • MRI
      • investigation of choice
      • fantastic contrast and spatial resolution
      • origin of tumors can be determined
      • different sequences are used to determine the likely diagnosis
      • specialized sequences can be useful to look at tumor metabolites