- : A type of brain tumor that is derived from oligodendrocytes which are cells in the central nervous system that surround and insulate the long fibers (the axons) through which nerves send their electrical messages.
* * *A relatively rare, relatively slowly growing glioma derived from oligodendrocytes that occurs most frequently in the cerebrum of adult persons; the neoplasm is grossly homogeneous, fairly well circumscribed, moderately firm, and somewhat gritty in consistency with interstitial calcification sufficiently dense so as to be detected by x-ray imaging of the skull. Microscopically, an o. is characterized by numerous small, round or ovoid, oligodendroglial cells with small, deeply stained nuclei (rarely observed in mitosis), and palely stained, indistinct cytoplasm; the neoplastic cells are rather uniformly distributed in a sparse, fibrillary stroma with scattered calcific bodies and an often prominent arcuate vasculature. [oligo- + G. dendron, tree, + glia, + -oma]- anaplastic o. an aggressive o. characterized by prominent nuclear pleomorphism, mitoses, and increased cellularity. SYN: pleomorphic o..
* * *oli·go·den·dro·gli·o·ma -.den-drō-glī-'ō-mə n, pl -mas also -ma·ta -mət-ə a tumor of the nervous system composed of oligodendroglia
* * *n.a tumour of the central nervous system derived from a type of glia (the supporting tissue) rather than from the nerve cells themselves. See also glioma.
* * *ol·i·go·den·dro·gli·o·ma (ol″ĭ-go-den″dro-gli-oґmə) a usually benign neoplasm derived from and composed of oligodendrocytes in varying stages of differentiation; the majority are seen in adults in the white matter of the brain. Called also oligodendroblastoma.
Medical dictionary. 2011.