Blastic plasmacytoid dendritic cell neoplasm is a very aggressive disease wich has been classified by the World Health Organization among “acute myeloid leukemia and related precursor neoplasms” in 2008. In aerly stages the skin is almost always the first affected site. Histological exam and immunophenotype are mandatory and necessary for the right diagnosis; its management is still a challenge. It is a rare (only 0.7% of cutaneous leukemia in western countries). Recently five patients affected by blastic plasmacytoid dendritic cell neoplasm came to our attention. They had different clinical manifestations at firts visit and diferent behaviour at the beginning, but they had the same immunohistochemical pattern and the same poor prognosis.
