CD4+CD56+ hematologic malignancy with primary cutaneous presentation has been well documented and is proposed as the malignant counterpart of pDC precursors (Chaperot et al., 2001; Adachi et al., 1994; Brody 1995; Uchiyama 1998; Petrella et al., 1999) and was named as blastic plasmacytoid dendritic cell neoplasm (BPDCN) (Facchetti et al., 2008). This evidence concerns the gene NCAM1 and CD4+/CD56+ hematodermic neoplasm.