Primary plasma cell leukemia (PCL) has a consistently ominous prognosis, even after progress in the last decades. PCL deserves a prompt identification to start the most effective treatment for this ultra-high-risk disease. The aim of this position paper is to revisit the diagnosis of PCL according to the presence of circulating plasma cells in patients otherwise meeting diagnostic criteria of multiple myeloma. We could identify two retrospective series where the question about what number of circulating plasma cells in peripheral blood should be used for defining PCL. The presence of ≥5% circulating plasma cells in patients with MM had a similar adverse prognostic impact as the previously defined PCL. Therefore, PCL should be defined by the presence of 5% or more circulating plasma cells in peripheral blood smears in patients otherwise diagnosed with symptomatic multiple myeloma.

即使在过去几十年取得进展后，原发性浆细胞白血病 (PCL) 的预后也一直不佳。PCL 值得迅速识别，以开始对这种超高风险疾病进行最有效的治疗。本立场文件的目的是根据患者体内循环浆细胞的存在重新审视 PCL 的诊断，否则符合多发性骨髓瘤的诊断标准。我们可以确定两个回顾性系列，其中关于外周血中循环浆细胞数量的问题应该用于定义 PCL。MM 患者中存在≥5% 的循环浆细胞具有与先前定义的 PCL 相似的不良预后影响。所以，