Blastic Plasmacytoid Dendritic Cell Neoplasm

Purpose of Review: Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare malignancy derived from plasmacyoid dendritic cells whose biology, clinical features, and treatment options are increasingly better understood. Recent Findings: TCF4 is a master regulator that drives donwstream transcriptional programs in BPDCN. In turn, TCF4 activity is dependent on the bromodomain and extra-terminal domain (BET) protein BRD4 whose inhibition provides a promising therapeutic vulnerability. Notably, TCF4 expression is a highly sensitive marker for BPDCN and augments diagnostic specificity alongside CD4, CD56, CD123, and TCL1. The gene expression profile of BPDCN is characterized by aberrant NF-kappaB pathway activation, while its genomic landscape is dominated by structural chromosomal alterations involving ETV6, MYC, and NR3C1, as well as mutations in epigenetic regulators particularly TET2. Summary: Advances in elucidating the biological characteristics of BPDCN are resulting in a more refined diagnostic approach and are opening novel therapeutic avenues for patients with this disease.