CD99 and neoplasm: In an attempt to immunologically characterize these neoplasms, a variety of IHC markers have been used.59 More consistently in the literature, expressions of CD34, factor XIIIa, vascular endothelial growth factor (VEGF), and CD99 were found, and the absence of any expression of S100, CD68, CD31, desmin, smooth muscle actin, and epithelial markers was noted.9,18,35,37,38,42,44