A case of blastic plasmacytoid dendritic cell neoplasm with ecchymotic lesions on the whole body.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) derived from plasmacytoid dendritic cell precursors is a very rare, and characterized by cutaneous and bone marrow involvement and leukemic spread. The neoplasm presents with an aggressive behavior, and the clinical findings include cytopenia, particularly thrombocytopenia. The tumor cells are negative for antigens of T- and B- cell lines. However, these cells express CD4, CD56 and CD123, which are markers of plasmacytoid dendritic cells, and negative for Epstein-Barr virus (EBV). From this point of view, a 71-year-old man who was initially found to have a cutaneous mass on his face and thorax was reported here, and initially was diagnosed as "eczema". The skin rashes then became aggravated on a trial of low dose topical corticosteroid for 2 months. According to skin biopsy, the tumor cells reveal an immature blastic appearance and positive for CD4 and CD56, negative for CD3, CD20, indicating a diagnosis of BPDCN. Here, we report the dismal course of a patient with BPDCN without accepting further therapy, and only survived 3 months.