Immunochemical results, available in June 2010, demonstrated positivity for cytokeratin (AE1 and AE3 clones), CD99 and MIC2 (Ewing’s sarcoma and 12E7 markers), PS100 (anti-human S-100), Wilm’s tumor 1 (WT1, 6 F-H2 clone), desmin (D33 clone), and vimentin (V9 clone), consistent with an immature teratoma. The gene discussed is CD99; the disease is Ewing sarcoma.