Figure 4: Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is morphologically composed of immature-appearing malignant cells with vesicular chromatin and inconspicuous nucleoli; occasional mitotic figures are present (A). The malignant cells show immunoreactivity for CD123 (B), TCL1 (C), TdT (D), MxA1 (E), CD56 (F), and are negative for CD3 (G), myeloperoxidase (H), and lysozyme (I).