Clinical Characteristics and Diagnosis of Acute Myeloid Leukemia with CD56-Blastic Plasmacytoid Dendritic Cell Neoplasm.

BACKGROUND

The aim of the study was to investigate the clinical characteristics and diagnosis of acute myeloid leukemia with CD56- blastic plasmacytoid dendritic cell neoplasm.

METHODS

The clinical characteristics and diagnosis of CD56-blastic plasmacytoid dendritic cell neoplasm and review related literature of 3 patients with acute myeloid leukemia were retrospectively analyzed.

RESULTS

This paper reports 3 cases and all were elderly men. The bone marrow features of three patients suggested the diagnosis of acute myeloid leukemia with blastic plasmacytoid dendritic cell neoplasm. Case 1: Flow cytometry showed that visible abnormalities in myeloid cells, accounting for 19.25% of nucleated cells, the phenotypes were CD117+, CD38+, CD33+, CD13+, CD123+, HLA-DR+, CD34 partial+, CD64 partial+ and TDT partial+, CD7-, CD11b-, CD22-, CD15-, CD5-, CD2-, CD20-, CD19-, CD10-, CD4-, CD14-, CD36, MPO-, CD9-, cCD79a-, cCD3-, mCD3-, CD5-. In addition, a group of abnormal plasmacytoid dendritic cells was observed, accounting for 13.83% of nuclear cells (CD2-, TDT partial+, CD303+, CD304+, CD123+, CD34-, HLA-DR+, and CD56-). Second generation sequencing: RUNX1 mutation 41.7%, DNMT3A mutation 41.3%. Case 2: Flow cytometry showed that visible abnormalities in myeloid cells, accounting for 33.66% of nucleated cells, express the strong expression of CD34 expression of CD117, HLA - DR, CD38, CD13, CD33, CD123, the TDT, no expression of MPO, cCD3, and cCD79a, conform to the AML phenotype. In addition, a group of abnormal plasmacytoid dendritic cells was observed, accounting for 26.87% of nucleated cells (CD303+, CD304+, CD123++, HLA-DR+, CD33+, CD36+, CD7 dim, CD4+, CD56-, TDT-). Second generation sequencing: The mutations of FLT3, CBL, RUNX1, and SRSF2 were 7.4%, 7.5%, 53.3%, and 29.9%. Case 3: Flow cytometry showed that visible abnormalities in myeloid cells, accounting for 23.76% of nucleated cells, the phenotypes were CD117++, HLA-DR++, CD34++, CD38+, CD13+, CD123+, CD7 partial+, and CD33 partial+, MPO-, TDT-, cCD3-, cCD79a-. In addition, a group of abnormal plasmacytoid dendritic cells was observed, accounting for 16.66% of nuclear cells (TDT+, CD303+, CD304+, CD 123++, HLA-DR+, CD38+, CD7+, CD56-, CD34-).

CONCLUSIONS

Acute myeloid leukemia with CD56-blastic plasmacytoid dendritic cell neoplasm is extremely rare and no special clinical manifestations are found, and the diagnosis is based on bone marrow cytology and immunophenotyping. There is no standard regimen for treatment of acute myeloid leukemia with mature blastic plasmacytoid dendritic cell neoplasm, and the prognosis depends on the progression of acute myeloid leukemia.