Blastic plasmacytoid dendritic cell neoplasm (BPDCN) and chronic myelomonocytic leukemia (CMML), An association with common clonality

Case Presentation: In autumn of 2016 a 62 year old man with history of diabetes mellitus, hypertension and dyslipidemia referred for his skin lesions and mild thrombocytopenia to the Hospital Clinic in Barcelona, Spain. Introduction: Skin biopsy showed a diffuse dermal infiltration of neoplastic cells that were positive for CD56, CD123, TCL1, CD33, CD2, BCL-2, TdT (only in 20% of cells), CD7 and negative for CD4,CD8, CD10, CD20, CD23,CD25,CD30, CD34,CD68 (Kp1),CD117, MPO, ALK and S-100 markers. Ki-67 was about 20%. EBER was also non-reactive. A primary diagnosis of Blastic Plasmacytoid Dendritic Cell Neoplasm was suggested. A review of patient’s previous laboratory tests showed he had had a history of monocytosis since November-2013 that missed by his family physician. In new bone marrow aspiration and biopsy, dysplastic changes in myeloid and megakaryocytic lineage were noted as well as a cellular marrow (70%) with diffuse infiltration of myelomonocytic cells which were positive for myeloperoxidase(MPO), Lysozyme and partial CD68 reactivity with no expression for CD4,CD56, CD117,CD34,CD3,CD123 and TdT . In peripheral blood flow cytometry, 25% mature monocytes(CD14+,CD64+,CD45+,HLADR+,CD300+,CD56neg ) with no expression of CD56 and very small numbers of dendritic cell (HLA-DR+ , CD304+ ) population (0.03%) were noted. In addition, in bone marrow flow cytometry a 16% of monocytic lineage in several stages of maturation (CD45+, CD64+, HLA-DR+, CD34neg ) and no expression of CD56 were found. There was 0.01% dendritic cells (HLA-DR+ , CD304+ ) in marrow . The patients karyotype was 46XY and normal. Molecular studies showed negative mutation study for FLT3-ITD gene in skin and bone marrow samples and Next generation sequencing (NGS) performed by total analysis of 19 acute myeloid leukemia related genes (using 267 amplicons) showed mutations in ASXL1,TET2 (in two different loci) in skin and mutations of ASXL1, TET2 ((in two different loci) and CBL in bone marrow . Discussion: Taking all together the final diagnosis changed to chronic myelomonocytic leukemia associated with blastic plasmacytoid dendritic cell neoplasm with a shared clone. The patient has been treated with azacythidine and candidated for bone marrow transplantation.

کلیدواژه ها:

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) ، chronic myelomonocytic leukemia (CMML) ، common clonality