How should we diagnose and treat blastic plasmacytoid dendritic cell neoplasm patients?
Authors: Garnache-Ottou Francine , Vidal Chrystelle , Biichlé Sabeha , Renosi Florian , Poret Eve , Pagadoy Maïder , Desmarets Maxime , Roggy Anne , Seilles Estelle , Soret Lou , Schillinger Françoise , Puyraimond Sandrine , Petrella Tony , Preudhomme Claude , Roumier Christophe , MacIntyre Elisabeth A. , Harrivel Véronique , Desbrosses Yohan , Gruson Bérengère , Geneviève Franck , Thepot Sylvain , Drebit Yuriy , Leguay Thibaut , Gros François-Xavier , Lechevalier Nicolas , Saussoy Pascale , Salaun Véronique , Cornet Edouard , Benseddik Zehaira , Veyrat-Masson Richard , Wagner-Ballon Orianne , Salanoubat Célia , Maynadié Marc , Guy Julien , Caillot Denis , Jacob Marie-Christine , Cahn Jean-Yves , Gressin Rémy , Rose Johann , Quesnel Bruno , Guerin Estelle , Trimoreau Franck , Feuillard Jean , Gourin Marie-Pierre , Plesa Adriana , Baseggio Lucile , Arnoux Isabelle , Vey Norbert , Blaise Didier , Lacroix Romaric , Arnoulet Christine , Benet Blandine , Dorvaux Véronique , Bret Caroline , Drenou Bernard , Debliquis Agathe , Latger-Cannard Véronique , Bonmati Caroline , Bene Marie-Christine , Peterlin Pierre , Ticchioni Michel , Rohrlich Pierre-Simon , Arnaud Anne , Wickenhauser Stefan , Bardet Valérie , Brechignac Sabine , Papoular Benjamin , Raggueneau Victoria , Vargaftig Jacques , Letestu Rémi , Lusina Daniel , Braun Thorsten , Foissaud Vincent , Tamburini Jérôme , Bennani Hind , Freynet Nicolas , Cordonnier Catherine , Le Garff-Tavernier Magali , Jacques Nathalie , Maloum Karim , Roos-Weil Damien , Bouscary Didier , Asnafi Vahid , Lhermitte Ludovic , Suarez Felipe , Lengline Etienne , Féger Frédéric , Battipaglia Giorgia , Mohty Mohamad , Bouyer Sabrina , Ghoual Ouda , Dindinaud Elodie , Basle Caroline , Puyade Mathieu , Lafon Carinne , Fest Thierry , Roussel Mikael , Cahu Xavier , Bera Elsa , Daliphard Sylvie , Jardin Fabrice , Campos Lydia , Solly Françoise , Guyotat Denis , Galoisy Anne-Cécile , Eischen Alice , Mayeur-Rousse Caroline , Guffroy Blandine , Recher Christian , Loosveld Marie , Garnier Alice , Barlogis Vincent , Rosenthal Maria Alessandra , Brun Sophie , Contentin Nathalie , Maury Sébastien , Callanan Mary , Lefebvre Christine , Maillard Natacha , Okamba Patricia , Ferrand Christophe , Adotevi Olivier , Saas Philippe , Angelot-Delettre Fanny , Binda Delphine , Deconinck Eric 
Published: December 2019

Abstract
Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive leukemia for which we developed a nationwide network to collect data from new cases diagnosed in France. In a retrospective, observational study of 86 patients (2000-2013), we described clinical and biological data focusing on morphologies and immunophenotype. We found expression of markers associated with plasmacytoid dendritic cell origin (HLA-DRhigh, CD303+, CD304+, and cTCL1+) plus CD4 and CD56 and frequent expression of isolated markers from the myeloid, B-, and T-lymphoid lineages, whereas specific markers (myeloperoxidase, CD14, cCD3, CD19, and cCD22) were not expressed. Fifty-one percent of cytogenetic abnormalities impact chromosomes 13, 12, 9, and 15. Myelemia was associated with an adverse prognosis. We categorized chemotherapeutic regimens into 5 groups: acute myeloid leukemia (AML)–like, acute lymphoid leukemia (ALL)–like, lymphoma (cyclophosphamide, doxorubicin, vincristine, and prednisone [CHOP])–like, high-dose methotrexate with asparaginase (Aspa-MTX) chemotherapies, and not otherwise specified (NOS) treatments. Thirty patients received allogeneic hematopoietic cell transplantation (allo-HCT), and 4 patients received autologous hematopoietic cell transplantation. There was no difference in survival between patients receiving AML-like, ALL-like, or Aspa-MTX regimens; survival was longer in patients who received AML-like, ALL-like, or Aspa-MTX regimens than in those who received CHOP-like regimens or NOS. Eleven patients are in persistent complete remission after allo-HCT with a median survival of 49 months vs 8 for other patients. Our series confirms a high response rate with a lower toxicity profile with the Aspa-MTX regimen, offering the best chance of access to hematopoietic cell transplantation and a possible cure.