What Is Happening to This Patient With a Rare Leukemia?

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare cancer with primary sites in the skin and bone marrow and secondary sites in the lymph nodes, spleen, and central nervous system. First described in the 1990s, these cells express a CD123 antigen hinting at a plasmacytoid dendritic cell origin. A CD123-directed cytotoxin called SL-401 was approved by the US Food and Drug Administration and the European Medicines Agency. During BPDCN treatment, a life-threatening syndrome can occur, but early awareness leads to positive patient outcomes.