1) Brain tumor 2) Brain tumour 3) Nearly always fatal 4) Spongioblastoma 1) Spongioblastoma 
A rapidly growing tumor composed of primitive glial cells, mainly arising from astrocytes.
A fast-growing type of central nervous system tumor that forms from glial (supportive) tissue of the brain and spinal cord and has cells that look very different from normal cells. Glioblastoma usually occurs in adults and affects the brain more often than the spinal cord. Also called GBM, glioblastoma multiforme, and grade IV astrocytoma.
Synonym for glioblastoma multiforme ... <oncology, tumour> A malignant brain tumour that accounts for 75% of glial tumours (arising from glial cells in the brain). Treatment is difficult and consists of a combination of radiation therapy and surgery. ... (17 Dec 1997) ... 
(gli″o-blas-to´mә) any malignant astrocytoma. glioblastoma multiforme astrocytoma grade III or IV; a rapidly growing tumor, usually of the cerebral hemispheres, composed of spongioblasts, astroblasts, and astrocytes.
Highly malignant brain tumour derived from glial cells.
[n] - a fast-growing malignant brain tumor composed of spongioblasts
The most common brain tumour found in adults. Also called Grade IV astrocytoma.