Background: "Agranular CD4+ CD56+ hematodermic neoplasm" are rare hematologic neoplasms which were recently shown to correspond to the plasmocytoid dendritic cells.
Case report: A 83-year-old presented isolated skin lesions purple, infiltrating the dermis. The biopsy has shown a dense dermal infiltration with malignant cells CD4+ CD56+ CD43+. There were no bone marrow involvement and no circulating blood cells. A chemotherapy permitted a clinical remission after six courses. Unfortunately, skin and blood relapses appear four months later. After a short success of chemotherapy by DHAP, the patient died three month later.
Discussion: "Agranular CD4+ CD56+ hematodermic neoplasm" is a distinct entity from the cutaneous primary lymphomas. Recently plasmocytoid monocyte cells have been identified as the precursor of the malignant population with the high expression of CD123, IL3 receptor. It is a distinct clinicopathologic entity by its clinical presentation with skin tropism, bone marrow involvement with or without leukemic phase and poor prognosis independent of the kind of treatment and its particular phenotype CD4+ CD56+ CD43+. It would be interesting to use antibodies linked to CD123 in therapeutic because any treatment have efficacity in this disease.