TABLE 2.

Immunophenotypic Profiles of Normal PDCs, “Tumor Forming” PDC Proliferations Associated With Myeloid Neoplasms, and BPDCN

Antigen	Normal PDCs	“Tumor forming” PDC Proliferations	BPDCN
CD123	+	+	+
TCL1	+	+	+
CD4	+	+	+
CD56	−*	±†	+‡
TdT	−	−	±
Ki-67	<5%	< 10%	> 30%

^*Positivity reported in a small subset of circulating PDCs.

^†Usually negative but may show focal positivity.

^‡Negative cases extremely rare.

BPDCN indicates blastic plasmacytoid dendritic cell neoplasm; PDC, plasmacytoid dendritic cell; TCL, T-cell leukemia/lymphoma; TdT, terminal deoxynucleotidyl transferase.