A 31-year-old male with a plasmacytoid dendritic blast cell neoplasm.

Plasmacytoid blast dendritic cell neoplasm is a rare subtype of acute leukaemia that represents less than 1% of haematologic neoplasms. It is characterised by skin involvement and leukaemic dissemination in the rest of the body. The immunophenotype is represented by the expression of CD4, CD56 and CD123.