Simultaneous deletion of 3'ETV6 and 5' EWSR1 genes in blastic plasmacytoid dendritic cell neoplasm: Case report and literature review

Background: Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematologic malignancy. 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. Case presentation: 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. Notably, these aberrations were identified in bone marrow myeloid precursors in the absence of bone marrow involvement by BPDCN. Conclusion: Analysis of 46 BPDCN cases with abnormal karyotypes (45 from literature reports plus this case) showed that 12p- is one of the most common structural aberrations in BPDCN. The ETV6 and CDKN1B on 12p deserve further investigations as potential markers of BPDCN.