Blastic plasmacytoid dendritic cell neoplasm with extensive cutaneous and central nervous system involvement.

Blastic plasmacytoid dendritic neoplasm is an exceedingly rare tumor that has undergone several changes in nomenclature over the last two decades, largely because of confusion regarding its cell of origin. It does, however, have distinctive clinical features with a particularly aggressive clinical course and no standard treatment. Overall, prognosis is poor and relapse is routine after initial response to chemotherapy. In this report, we describe a typical patient with this disease and reconcile the available literature and its evolution. We emphasize the leukemic nature of this tumor's behavior, with extensive central nervous system and skin involvement, and describe for the first time a potential role for maintenance chemotherapy in its treatment.