Abstract :
The role of plasmacytoid dendritic cell (pDC) proliferation in acute myeloid leukemia (AML) is less understood. There are two polar pDC neoplasms recognized by World Health Organization (WHO) currently, including blastic plasmacytoid dendritic cell neoplasm, and mature plasmacytoid dendritic cell proliferation in myeloid neoplasms. Morphologically, AMLs showing a gamut of pDCs ranging from blastic to immature pDCs, to more mature forms, fall outside the literal purview of these two entities. With genetic studies proving that pDCs in such cases share the same mutational profile as leukemic blasts, they may be more aptly designated as AML with pDC differentiation (pDC-AML). Flow cytometry is required to demonstrate pDC-AML, and their clonality is established by genetic studies. However, it is difficult to prove their leukemic nature on morphology. We present a case of pDC-AML with pDCs showing presence of Auer rods. To the best of our knowledge this is the first case with morphological evidence of leukemic pDCs.
Keyword :
Acute myeloid leukemia, pDC differentiation, Auer rods, flow cytometry, RUNX1.