OLIG2 and neoplasm: One case (#14) was clearly distinct, having a polymorphous morphology composed of a predominant glioneuronal pattern with eosinophilic granular bodies, perivascular inflammatory infiltrates, CD34 extravascular cellular staining, GFAP, OLIG2 and synaptophysin expression in a large part of the tumor cells, admixed with clear cells, small round cells, and focal epithelioid cells.