Based on literature reports of limited cases, over 50 % of BPDCN have chromosomal abnormalities, but no single chromosomal change has been identified as diagnostic of this entity.<h4>Case presentation</h4>In this report, we present a case of BPDCN with complicated chromosomal abnormalities involving chromosomes 12 and 22 and resulting in a simultaneous partial deletion of ETV6 and EWSR1. The gene discussed is EWSR1; the disease is CD4+/CD56+ hematodermic neoplasm.