NCIt definition : A tumor of the brain or spinal cord showing astrocytic differentiation. It includes
the following clinicopathological entities: pilocytic astrocytoma, diffuse astrocytoma,
anaplastic astrocytoma, pleomorphic xanthoastrocytoma, and subependymal giant cell
astrocytoma.;
Alternative definition : NICHD: A malignant neoplasm of the central nervous system that arises from astrocytes.; NCI-GLOSS: A tumor that begins in the brain or spinal cord in small, star-shaped cells
called astrocytes.;