Brain cancer (glioblastoma). Light micrograph of a section through tissue from a spongioblastoma (or glioblastoma). Normal brain tissue is regular in appearance. This tissue displays chaotic growth of irregular cells, typical of cancer. A glioblastoma is an aggressive type of brain tumour that arises from non-nervous (glial) tissue in the brain. It grows rapidly, destroying healthy tissue and damaging brain function. The prognosis is very poor, with treatment being palliative, aiming to slow the growth of the tumour and alleviate the symptoms. Magnification unknown.