[Clinical Analysis of Patients with Blastic Plasmacytoid Dendritic Cell Neoplasm]

To explore the clinical characteristics, treatment, and prognosis of patients with blastic plasmacytoid dendritic cell neoplasm(BPDCN).

Clinical data of 5 patients diagnosed with BPDCN in Wuhan First Hospital and Wuhan Tongji Hospital from June 2016 to November 2021 were retrospectively analyzed.

Among the 5 patients, 3 were male and 2 were female, with a median age of 28(10-52) years old. Four patients showed obvious skin damage at the initial diagnosis; the other one showed clinical manifestations of acute leukemia rather than obvious skin damage at the initial diagnosis, but infiltrated skin when the disease relapsed after treatment. Other infiltration sites of lesions included bone marrow (2/5), peripheral blood (2/5), lymph nodes (3/5), liver and spleen (2/5). All patients had no clinical manifestation of central nervous system infiltration. Tumor cell specific immune markers CD4, CD56, CD123 were all positive, and the median Ki-67 index was 70%. TET2, ASXL1 and NRAS gene mutations were found respectively in 3 patients by next-generation sequencing technique (NGS). ALL-like, AML-like and invasive NK/T cell lymphoma-like first-line induction chemotherapy regimens were used for the patients. One patient died of severe complications during the early stage of chemotherapy, 3 patients were evaluated as CR, and 1 patient was evaluated as PR. 2 patients were recurred and progressed after induction of chemotherapy, and one of them was evaluated as CR after re-treatment. One patient received autologous hematopoietic stem cell transplantation (auto-HSCT) and got long-term survival (OS 87 months). 3 patients received allogeneic hematopoietic stem cell transplantation (allo-HSCT), of which one died of transplantation related complications, and 2 cases survived. The median follow-up time of 4 patients with evaluable efficacy was 28.5(9-84) months, the median OS time was 31.5(10-87) months.

BPDCN is a highly heterogeneous malignant tumor with a poor prognosis. HSCT, especially allo-HSCT can significantly improve the prognosis of BPDCN patients.