Astrocytoma

Synonyms

Anaplastic astrocytoma; Astrocytic tumor; Diffuse astrocytoma; Diffuse intrinsic pontine glioma; Glioblastoma; Pilocytic astrocytoma; Pleomorphic xanthoastrocytoma; Subependymal giant cell astrocytoma

Definition

Astrocytomas are primary glial tumors of the central nervous system that occur in the brain and occasionally the spinal cord. Glial tumors, or gliomas, are classified by the World Health Organization (WHO) according to histologic resemblance to astrocytes, oligodendrocytes, or ependymal cells, and then numerically graded (I to IV) for pathologic features of malignancy. Astrocytomas account for at least 76 % of all gliomas and constitute a heterogeneous group of astrocytic tumors with distinct clinical and molecular features. More generally, however, astrocytomas can be divided into the diffusely infiltrative astrocytic tumors (grades II–IV) that occur more commonly in adults and the more circumscribed astrocytic tumors (grade I) that occur more commonly in children....