Blastic plasmacytoid dendritic cell neoplasm: evolving insights in an aggressive hematopoietic malignancy with a predilection of skin involvement.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) derived from precursors of plasmacytoid dendritic cells is a very rare, unique, and highly aggressive immature hematopoietic malignancy, more frequently occurring among healthy elderly adults. BPDCN can be characterized by a striking predilection for cutaneous involvement, which is often detected incidentally by dermatologists and is difficult to clinically distinguish it from other primary skin lesions and histologically from leukemia/lymphoma cutis. Thus, histological diagnosis of cutaneous biopsies is crucial to correctly classify this entity. Most patients eventually progress to acute myeloid leukemia and are generally not curable. Here, we present 2 cases of classic BPDCN and discuss the origin of tumor and literature-based characteristic clinical and morphological features, evolving immunomarkers, and molecular genetic aspects of this neoplasm.