[Plasma cell leukemia]

Plasma cell leukemia (PCL) is a rare disorder which develops spontaneously (primary PCL) or evolves in patients with multiple myeloma (secondary PCL). It is defined by the presence of 2 × 10(9)/L peripheral blood plasma cells or plasmacytosis accounting for more than 20 % of the differential white cell count. PCL presents more often extramedullary involvement, anemia, thrombocytopenia, hypercalcemia, as well as impaired renal function. Cytogenetic abnormalities and mutations observed in PCL lead to escape from immune surveillance and independence from the bone marrow microenvironment with changes in expression of adhesion molecules or chemokines receptors. The outcome of PCL has improved with combination approaches with novel agents (including bortezomib and immunomodulatory drugs, such as lenalidomide) and with autologous stem cell transplantation. Allogeneic hematopoietic stem cell transplantation is currently available for young patients. This article is an overview of this rare and severe disease and the different therapeutics options that are recommended.