GFAP and neoplasm: The tumor cells were diffusely positive for GFAP (Fig. 3e), CD56 (Fig. 3f), S100 (Fig. 3g), and vimentin, but negative for CD34 (Fig. 3b), synaptophysin (Fig. 3h), olig2 (Fig. 3i), inhibin-α (Fig. 3j), NeuN (Fig. 3k), D2-40, P53 and IDH1.