The immunohistochemical result of the ovarian tumor was vimentin (+), AE1/AE3 (weakly, +), CK7 (−), EMA (−), CD117 (scattered +), ER (−), PR (+), CD99 (+), a-inhibin (single +), CD56 (+), CD30 (−), PLAP (−), SALL4 (−), OCT3/4 (−), HCG (−), Ki67 (approximately 30%, +), CK8 (−), SMA (+), desmin (−), and S-100 (−). This evidence concerns the gene CD99 and ovarian neoplasm.