CD99 and neoplasm: The tumor tissue of patient 2 was immunohistochemically positive for vimentin, EMA, CK7 and CK20; and negative for CD56, CD10, WT-1, CD34, CD57, P53, CD117, TTF-1, CD15, CD99, TG, chromogranin A and Syn; with a Ki-67 LI of 20%.