Primitive neuroectodermal tumours (PNETS)
40% of all cancers spread to the brain
These tumours develop from cells that are left over from the earliest development of the body in the womb.
Normally these cells are harmless, but sometimes they can become cancerous. PNETs are very similar to medulloblastomas and mainly occur in children, but are also diagnosed in young adults. The tumours are fast-growing, normally growing in the cerebellum, and can spread to other parts of the brain and to the spinal cord through the cerebrospinal fluid (CSF).