Totally agree .. neurons are non dividing cells ..

that is true yet malignancy of the central nervous system are primary which originate from the brain or spinal cord or secondary that is metastasizing from elsewhere ..

the primary one is named after its cell of origin .. you will find astrocytoma .. oligodendroglioma .. ependymoma and so on

all are glial cells that actually are proliferating cells that fill in spaces for example after stroke to form gliosis so why not proliferate in an abnormal fashion and cause malignancy .. this is for adult brain

as for pediatric the most common malignancy is meduloblastoma which usually take place along the posterior fossa structures like the cerebellum that is still growing and maturing in children so false growth may be the initiator of malignancy in this age group.

Thanks