26th June 2023

Classification of brain tumours

There are 3 common different ways to subdivide brain tumours:

• Intrinsic vs Extrinsic
  • ‘Intrinsic’ tumours are classified as tumours arising from within the brain. Those that grow from structures around the brain, such as cranial nerves, spinal nerves and dura, are classified as ‘extrinsic’ tumours.
• Benign vs Malignant
  • Slow-growing tumours such as schwannomas and meningiomas tend to be benign, however, tumours such as gliomas are usually malignant.
• Primary vs Secondary: Primary tumours are those that originate from the cranial tissues, whilst secondary tumours are metastatic and have spread from elsewhere in the body. A full body CT can help to establish whether there are any other tumours within the body. Metastatic (secondary) brain tumours are three times more common than primary brain tumours. A biopsy can determine the tissue of the tumour. Lung, breast, bowel, skin, and kidney tumours are the most common sites that metastasise to the brain.