[A case of blastic plasmacytoid dendritic cell neoplasm involving the skin]

A 81 year-old male patient visited our hospital on February, 2011 because he found the subcutaneous tumor on his back. The dermatologist performed skin biopsy and found that large atypical cells diffusely proliferated in the sub-epidermal and subcutaneous tissue. Two month later, we diagnosed him as blastic plasmacytoid dendritic cell tumor, as the blastic cells in the lymph node were CD4+, CD56+, CD3-, CD5-, CD20-, CD138-, MPO-, granzyme B-, TCL1+. None of the gene rearrangements of T-cell receptor and immunoglobulin was negative in the lymph node. The tumor was relapsed after 3 courses of COP therapy and the patient failed to respond to the salvage therapies such as CEPP and FMD therapy. As this tumor is rare and there are no standard regimens, we reviewed the past case series and discussed about the pathogenesis, clinical course and treatment options of this tumor in this article.