CD34 and schwannoma: These showed typical features of schwannoma, with Antoni A (cells forming a typical palisade arrangement in a well-organized pattern) and Antoni B (loose cells without palisade architecture) regions in variable proportions (Fig. 3A) and cells with strong positivity for S100 protein (Fig. 3B) but negative results for CD117, discovered on gastrointestinal stromal tumors protein 1 (DOG1), desmin, smooth muscle actin (SMA), CD34, CgA and pancytokeratin, as determined using IHC assay.