Blastic plasmacytoid dendritic cell neoplasm: single-center experience with two cases in one year.

To the Editor, A 78-year-old Caucasian female patient presented to our department with a cutaneous lesion on her right shoulder (Figure 1a). Laboratory data disclosed mild anemia (hemoglobin: 11.3 g/dL) thrombocytopenia (139x109/L) and 30% morphologically immature atypical cells in the peripheral blood. Bone marrow aspiration showed 5% infiltration of immature blast cells with the following immunophenotype: CD45 (+), CD123 (+), CD85k (+), CD33 (-), CD14 (-), CD16 (-), CD19 (-), CD5 (-), CD10 (-), CD20 (-), CD56 (+) 20%, CD4 (+), NG2 (+). No chromosomal alterations were detected by cytogenetic analysis of the bone marrow (46,XX). Specific karyotypic aberrations were not found. She had axillary, jugular, submandibular, and supraclavicular lymphadenopathy. Cutaneous, lymph node, and bone marrow biopsy confirmed the diagnosis of blastic plasmacytoid dendritic cell neoplasm (BPDCN). She was treated with cyclophosphamide, vincristine, adriamycin, and dexamethasone (Cy-VAD) as part of an acute lymphoblastic leukemia treatment-protocol. She achieved first complete remission. Due to the highly aggressive type of leukemia, we decided to continue with induction 2 chemotherapy (etoposide-cytosine arabinoside), but she died 5 months after the first sign due to multiorgan failure. One year later, a 75-year-old Caucasian male patient presented with a generalized purplish skin rash from the head to the lower extremities that expanded very rapidly (Figure 1b and 1c). Laboratory data revealed anemia (hemoglobin: 10.9 g/dL), thrombocytopenia (100x109/L), and 42% morphologically immature atypical cells in the peripheral blood. Bone marrow aspiration showed 88% infiltration of immature blast cells with the following immunophenotype: CD45 (+) low, CD43 (+), CD123 (+), CD56 (+), CD4 (+), CD34 (-). Computed tomography scans did not disclose pathologic lymphadenopathy. Histopathology of skin lesions showed blast cell infiltrate. Immunohistochemical analysis confirmed the presence of cells with the aforementioned immunophenotypic features. A basic immunophenotype with CD4 (+), CD56 (+), CD123 (+), and negative T, B, and NK cells led to the diagnosis of BPDCN as per the current WHO classification [1]. In the cytogenetic analysis, a pathologic karyotype was found (46,XY, del (12), (p12), del (17), (p11) [17]/46,XY [13]). He began acute myeloid leukemia-type chemotherapy with idarubicin and arabinoside-c and he achieved complete remission after induction. We changed his treatment plans and continued with CHOP due to his poor performance status, and, after 4 cycles, he still remains Blastic Plasmacytoid Dendritic Cell Neoplasm: Single-Center Experience with Two Cases in One Year Blastik Plazmasitoid Dendritik Hücreli Neoplazi: Bir Yılda İki Olguyu İçeren Tek Merkez Deneyimi