Clinical analysis of blastic plasmacytoid dendritic cell neoplasm

Abstract

Objective To investigate the clinical features, diagnosis, treatment and efficacy of blastic plasmacytoid dendritic cell neoplasm (BPDCN) in order to improve the understanding of BPDCN. Methods On 21 August 2017, a case of BPDCN patient admitted in Hematology Department of Beijing Tsinghua Changgung Hospital affiliated to Tsinghua University, was included in this study. This patient was diagnosed as BPDCN in other hospital in November 2016, and then received 5 courses of CHOP (cyclophosphamide+ doxorubicin+ vincristine+ prednisone)-21 regimen for chemotherapy. After partial remission (PR), the patient relapsed in June 2017, and was admitted in Hematology Department of our hospital for further treatment. After admission, combined with the patient′s medical history, diagnosis was made according to the clinical manifestations, bone marrow examination and relevant laboratory examination results. On 25 August 2017, the patient received 3 courses of VDCP (vindesine+ daunorubicin+ cyclophosphamide+ dexamethasone) regimen for chemotherapy. Vindesine 4 mg/d, d1, 8, 15, 22; doxorubicin 60 mg/d, d4-5, 80 mg/d, d6, 60 mg/d, d15-16; cyclophosphamide 1.7 g/d, d4, 15; and dexamethasone 17 mg/d, d1-7 were applied. The laboratory test results, further diagnosis and assesement of disease, and curative effects of this patient were analyzed retrospectively, and related literature was reviewed to explore the research progress of BPDCN diagnosis and treatment. Results ① After admission, flow cytometry test results of the patients′ bone marrow cells showed abnormal cell population within original cell distribution area, accounting for about 9.4%. Abnormal cell expressed human leukocyte antigen (HLA)-DR, CD4, CD38, CD56 and CD123, and some expressed CD33. Results of morphological examination of bone marrow cells showed that proliferation of bone marrow cells was significantly active. Proportion of granulocyte was 38.0%, proportion of erythroid was 24.0%, and ratio of granulocyte and erythroid was 1.58∶1. Megakaryotic cells and heteromorphic lymphoid cells could be seen. Ratio of primitive cells was 27.0%, and was BPDCN bone marrow invasion. Bone marrow cell immunohistochemical test results showed CD4 (+ ), CD56 (+ ), CD123 (+ ), CD68 (+ ), CD235 (erythroid+ ), myeloperoxidase (MPO) (granulocyte+ ), terminal deoxynucleotidyl transferase (TdT) (-), CD117 (<1%), CD3 (-), CD20 (-), CD23 (-), T cell intracellular antigen (TIA)-1 (+ ), granzyme B (-). Results of scalp biopsy showed that tumor cells were diffuse in dermal layer of the skin without involving the epidermis. Immunohistochemical results showed that CD4 (+ ), CD43 (+ ), CD56 (+ ), CD123 (weak+ ), TdT (scattered+ ), CD117 (-), CD3 (-), CD23 (-), TIA-1 (-), granzyme B (-), and CD68 (scattered+ ). ② The patient was diagnosed with BPDCN, and was comprehensively evaluated as progressive disease (PD) at admission. ③ After the treatment with VDCP regimen, all rashes on the scalp, face and trunk of the patient were eliminated. The granulocyte count returned to the normal reference range. Bone marrow smear results showed that bone marrow hyperplasia was significantly active, with 50.0% granulocytes and 36.5% erythroid. Ratio of granulocytes and red line cells was 1.37∶1. Proportion of primitive granulocytes and abnormal lymphocytes were 0.5% and 3.5%, respectively. The comprehensive evaluation was complete remission (CR). The patient refused to continue treatment and died 20 months after the onset (February 2018). Conclusion BPDCN is a rare and highly aggressive disease with poor prognosis, and standard treatment protocols for BPDCN has not been established currently. Key words: Dendritic cells; Killer cells, natural; Drug therapy; Prognosis; Blastic plasmacytoid dendritic cell neoplasm