Immunohistochemical staining showed a Ki67 index of 8% in the tumour cells (Fig. 3b), strong and diffuse positivity for CD34 (Fig. 3c) and STAT6 (Fig. 3d), and zonal positivity for vimentin (Fig. 3d) and CD99 (Fig. 3f). This evidence concerns the gene CD99 and neoplasm.