Blastic Plasmacytoid Dendritic Cell Neoplasm: A Single-Center Experience Documenting Frequent CNS Involvement

Blastic Plasmacytoid Dendritic Cell Neoplasm (BPDCN) is a rare myeloid malignancy that often manifests with skin, lymph node, and bone marrow involvement. Patients diagnosed with BPDCN have a poor prognosis, with a median overall survival ranging from 12-14 months (Julia et al., 2014). Aoki et. al (2015) published a retrospective review reporting overall survival at 4 years for patients who underwent autologous and allogeneic hematopoietic stem cell transplant (HSCT) as 82% and 53%, respectively. Progressive disease, including central nervous system (CNS) involvement, excludes patients from receiving HSCT. Published case reports suggest that CNS presentation at diagnosis is rare, with estimates of only 10% of patients with CNS involvement at diagnosis (Feng et al., 2014; Starck et al., 2014). A retrospective case series of all patients treated for BPDCN at The Ohio State University from 1990 to present (n=11) was performed. Demographic data is summarized in table 1. Four of five patients undergoing CNS evaluation at diagnosis were found to have CNS involvement. All eleven patients underwent chemotherapy with the majority receiving induction chemotherapy (table 1). Three of the four patients with known CNS involvement at diagnosis expired within three months. The fourth patient survived with significant neurological complications secondary to intrathecal chemotherapy and was not a HSCT candidate. Two of eleven patients underwent HSCT. One died from relapsed disease in bone marrow, and one achieved long-term progression free survival. Two patients were lost to follow up, and were 7 and 16 months past diagnosis at last contact. CNS involvement with BPDCM at diagnosis may be more common than the literature suggests and should be investigated at diagnosis to allow these patients the best chance of long-term survival.