Plasma cell leukemia: from biology to treatment

Abstract

Plasma cell leukemia (PCL) is a very aggressive and rare form of malignant monoclonal gammopathy characterized by the presence of plasmocytes in peripheral blood. It is classified as primary PCL occuring 'de novo', or as secondary PCL in patients with relapsed/refractory multiple myeloma. Primary PCL is a distinct clinicopathological entity from myeloma with different cytogenetic abnormalities and molecular findings, which are usually found only in advanced multiple myeloma. The clinical course is aggressive with short remissions and reduced overall survival. The diagnostic criteria are based on the percentage (>20%) and absolute number (2 × 10(9) /L) of plasma cells in peripheral blood. After establishing diagnosis, induction therapy should begin promptly which is aimed to rapid disease control and to minimize the risk of early death. Intensive chemotherapy regimens and bortezomib-based regimens, followed by high-dose therapy with autologous stem cell transplantation, are recommended. Allogeneic transplantation can be considered in younger patients. This article reviews recent knowledge of this hematological malignancy that is associated with a very poor prognosis.

MYEOV gene overexpression in primary plasma cell leukemia with t(11;14)(q13;q32)

“…The current case presented a marked plasmablastic differentiation, a phenotype difficult to link with the molecular characteristics reported above. There are few reports in the literature describing the morphological features of circulating PCs in pPCL (2,18). However, certain cases were described with an irregular nuclear contour or containing multiple immature cells with a high nuclear-cytoplasmic ratio, finely dispersed chromatin, prominent nucleolus and limited or absent Golgi zone, which corresponded to blasts or plasmablasts (18).…”

“…Primary plasma cell leukemia (pPCL) is an uncommon form of plasma cell (PC) dyscrasia, and the most aggressive of the human monoclonal gammopathies (1,2). pPCL is characterized by the presence of >20% circulating PCs in peripheral blood and/or an absolute circulating PC count exceeding 2x10 9 cells/l (1).…”

“…pPCL is characterized by the presence of >20% circulating PCs in peripheral blood and/or an absolute circulating PC count exceeding 2x10 9 cells/l (1). Peripheral blood flow cytometry is an important tool to demonstrate the presence of PCs and to confirm their clonality, as well as to exclude other lymphoproliferative disorders such as low-grade B-cell and lymphoplasmacytic lymphoma (2). In regard to cytogenetic findings, the t(11;14)(q13;q32) rearrangement is the most common alteration in pPCL (3), promoting cyclin D1 (CCND1) gene overexpression due to its juxtaposition with the immunoglobulin heavy locus (IGH) chromosome region.…”

Prognostic impact of circulating plasma cells in patients with multiple myeloma: implications for plasma cell leukemia definition

“…3–5 PCL may be classified as primary when it presents de novo in patients without previous evidence of multiple myeloma (MM) or secondary when it is presented as a leukemic transformation of a previously recognized MM. Primary PCL is a rare entity with an incidence of 2 to 4% of MM 6–8 and is associated with a worse prognosis than MM.…”

Primary plasma cell leukemia: A case report and review of the literature

“…15 Multiparametric flow cytometry shows increased prevalence of CD20, CD44, CD45, CD19, and CD23 and lower CD9, CD56, CD117, and HLA-DR. 11,16 CD56 is a neuronal cell adhesion molecule that anchors plasma cells to the bone marrow stroma, preventing their migration to extramedullary sites. 17 Higher frequencies of t(4;14), t(11;14) and t(14;16) were observed in pPCL. 18 Translocation involving the immunoglobulin heavy chain (IgH) locus on 14q32 is present in more than 80% on pPCL with 25%-65% of IgH translocations in t(11;14) and is associated with leukemic transformation in MM.…”