IDH2 and acute myeloid leukemia: Next generation sequencing revealed four somatic driver mutations (<i>NRAS</i>-G13D, <i>IDH2</i>-R140Q, and <i>DNMT3A</i>-F640fs/-I715fs), equally shared by both the lymph node and bone marrow, suggesting a common clonal origin for the concurrent LCH and AML.