Plasma cell leukemia: consensus statement on diagnostic requirements, response criteria and treatment recommendations by the International Myeloma Working Group

Abstract

Plasma cell leukemia (PCL) is a rare and aggressive variant of myeloma characterized by the presence of circulating plasma cells. It is classified as either primary PCL occurring at diagnosis or as secondary PCL in patients with relapsed/refractory myeloma. Primary PCL is a distinct clinic-pathologic entity with different cytogenetic and molecular findings. The clinical course is aggressive with short remissions and survival duration. The diagnosis is based upon the percentage (≥ 20%) and absolute number (≥ 2 × 10 9/L) of plasma cells in the peripheral blood. It is proposed that the thresholds for diagnosis be reexamined and consensus recommendations are made for diagnosis, as well as, response and progression criteria. Induction therapy needs to begin promptly and have high clinical activity leading to rapid disease control in an effort to minimize the risk of early death. Intensive chemotherapy regimens and bortezomib-based regimens are recommended followed by high-dose therapy with autologous stem-cell transplantation (HDT/ASCT) if feasible. Allogeneic transplantation can be considered in younger patients. Prospective multicenter studies are required to provide revised definitions and better understanding of the pathogenesis of PCL.

Favorable long-term outcome of patients with multiple myeloma using a frontline tandem approach with autologous and non-myeloablative allogeneic transplantation

“…[7][8][9][10]15,16,[45][46][47] Our results are provocative and should be used to reactivate sound scientific discussion on the exact role of allogeneic transplant in the treatment of MM, 48,49 as further research is needed to optimize the GvMM effect and identify patients who might best benefit from it. Patients with poor prognosis (ISS III, 22 high-risk cytogenetics 42 and plasma cell leukemia 50 ) or younger patients who have the most significant loss in years of life following a diagnosis of MM 51 should be targeted in priority for a tandem approach like ours. Proteasome inhibitors, immunomodulatory drugs and monoclonal Abs among others could bring additional clinical benefits if used after NMA allogeneic transplant.…”

Primary Plasma Cell Leukaemia with Unusual Presentations: A Case Series

“…The presence of the myeloid antigen CD13 on myeloma cells is an uncommon finding [3]. Since CD13 antigen is expressed by cells of the granulocytic and monocytic lineages, its presence on plasma cells supports the hypothesis of an early stem cell disorder in the development of PCL.…”

“…The diagnostic criteria of PCL are (1) blood leukocyte count exceeding 10 9 10 9 /L, with at least 2 9 10 9 /L plasma cells, or (2) for a peripheral blood leukocyte count below 10 9 10 9 /L, at least 20 % of the circulating cells must be plasma cells [1][2][3]. Rarely PCL with aberrant morphologic features like cleaved, monocytoid or multi-lobulated nuclei has been reported [1,4,5].…”

Leukemia with Plasma Cells — Case Report

“…3 The clinical presentation of PCL at the beginning can be similar to MM, with the presence of anemic syndrome, which is more frequent at the start of the disease and is usually more severe. 4 The presence of hemorrhagic syndrome, because of thrombocytopenia, is more frequent in PCL patients.…”