Clinical diversity and treatment approaches to blastic plasmacytoid dendritic cell neoplasm: a retrospective multicentre study

Background Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare, aggressive type of haematologic precursor malignancy primarily often manifesting in the skin. We sought to provide a thorough clinical characterization and report our experience on therapeutic approaches toBPDCN. Methods In the present multicentric retrospective study, we collected allBPDCNcases occurring between 05/1999 and 03/2018 in 10 secondary care centres of the German-Swiss-Austrian cutaneous lymphoma working group. Results A total of 37BPDCNcases were identified and included. Almost 90% of the patients had systemic manifestations (bone marrow, lymph nodes, peripheral blood) in addition to skin involvement. The latter presented with various types of cutaneous lesions: nodular (in more than 2/3) and bruise-like (in 1/3) skin lesions, but also maculopapular exanthema (in circa 1/6). Therapeutically, 22 patients received diverse combinations of chemotherapeutic regimens and/or radiotherapy. Despite initial responses, all of them ultimately relapsed and died from progressive disease. Eleven patients underwent haematopoietic stem cell transplantation (HSCT; autologousHSCTn = 3, allo-HSCTn = 8). The mortality rate amongHSCTpatients was only 33.33% with a median survival time of 60.5 months. Conclusion Our study demonstrates the clinical diversity of cutaneousBPDCNmanifestations and the positive development observed after the introduction ofHSCT.