Therapeutic advances in the treatment of primary plasma cell leukemia: a focus on hematopoietic cell transplantation.

Primary plasma cell leukemia (pPCL) is an uncommon but aggressive plasma cell malignancy associated with frequent extramedullary involvement, high-risk cytogenetic abnormalities, and frequent organ dysfunction, ultimately resulting in poor prognosis. Here we review recent advances in our understanding of the molecular and biological aspects of PCL and summarize therapeutic progress occurring over the past 2 decades. pPCL is distinguished from secondary PCL arising from multiple myeloma. The molecular and immunophenotypic changes of pPCL are often distinct from those seen in secondary PCL and multiple myeloma. The availability of novel agents (ie, proteasome inhibitors and immunomodulatory agents) and the increasing use of hematopoietic cell transplantation strategies have resulted in better outcomes, although long-term survival remains poor. Development of complex treatment algorithms that combine novel agents as induction therapy, as part of conditioning regimens for hematopoietic cell transplantation (autologous or allogeneic), or as post-transplantation remission strategies are logical and may translate into improved survival in patients with PCL.