ABSTRACT
Introduction Oligodendroglial tumors (from the Greek words oligo meaning ‘few’, dendro meaning ‘tree’ and glia meaning ‘glue’, meaning few dendritic processes when compared with astrocyts) are believed to arise from the oligodendrocyte by dedifferentiation or from neoplastic transformation of a progenitor such as the O2A cell,83 a precursor of oligodendrocytes and type II astrocytes. The tumors occur both in pure form and mixed with neoplastic cells that appear astrocytic (oligoastrocytoma). Like diffuse astrocytomas, many tumors progress from low grade to a higher grade (Fig. 5.8).
