NKX2-2 and Ewing sarcoma: Although NKX2.2 immunohistochemistry and EWSR1 rearrangement studies were not available in our setting to definitively exclude BCOR- or CIC-rearranged sarcomas, the characteristic morphology and diffuse membranous CD99 positivity strongly supported the diagnosis of Ewing sarcoma (Figures 1, 2).