Primary plasma cell leukemia: report of 17 new cases treated with autologous or allogeneic stem-cell transplantation and review of the literature.

Primary plasma cell leukemia (PPCL) is a rare hematologic malignancy characterized by the proliferation of plasma cells in blood, bone marrow, and other organs in the absence of established multiple myeloma. PPCL has a poor prognosis when treated with conventional therapy for multiple myeloma. We describe here 17 new cases of PPCL who underwent stem-cell transplantation (SCT) (2 cases observed by the authors and 15 cases from the International Bone Marrow Transplant Registry [IBMTR]). The first case was diagnosed in a 21-year-old male who presented with leukocytosis and acute renal failure. He was treated with hyper-CVAD, entered complete remission, and then proceeded to high-dose chemotherapy with peripheral stem-cell support. He is currently in complete remission 23 months after initial diagnosis and 19 months after autologous SCT. The second case was observed in a 31-year-old male who presented with leukocytosis and hepatic infiltration with plasma cells. He was treated with VAD chemotherapy and underwent allogeneic bone marrow transplantation from his HLA-identical sister. He remained in complete remission for 3 years and then developed progressive refractory disease, dying 7 years after the initial diagnosis. In addition to these 2 cases, 15 further unpublished cases of PPCL from the IBMTR are reported here (treated between 1993 and 2001, 6 by autologous and 9 by allogeneic transplantation). Finally, the features of PPCL, the outcome, published data of SCT for PPCL, and indications for treatment are discussed.