Valent P, Sotlar K, Sperr W R, Escribano L, Yavuz S, Reiter A, George T I, Kluin-Nelemans H C, Hermine O, Butterfield J H, Hägglund H, Ustun C, Hornick J L, Triggiani M, Radia D, Akin C, Hartmann K, Gotlib J, Schwartz L B, Verstovsek S, Orfao A, Metcalfe D D, Arock M, Horny H-P
Division of Hematology, Department of Medicine I, Medical University of Vienna, Vienna, Austria.
Institute of Pathology, Ludwig-Maximilians-University, Munich, Germany.
Ann Oncol. 2014 Sep;25(9):1691-1700. doi: 10.1093/annonc/mdu047. Epub 2014 Mar 27.
Mast cell leukemia (MCL), the leukemic manifestation of systemic mastocytosis (SM), is characterized by leukemic expansion of immature mast cells (MCs) in the bone marrow (BM) and other internal organs; and a poor prognosis. In a subset of patients, circulating MCs are detectable. A major differential diagnosis to MCL is myelomastocytic leukemia (MML). Although criteria for both MCL and MML have been published, several questions remain concerning terminologies and subvariants. To discuss open issues, the EU/US-consensus group and the European Competence Network on Mastocytosis (ECNM) launched a series of meetings and workshops in 2011-2013. Resulting discussions and outcomes are provided in this article. The group recommends that MML be recognized as a distinct condition defined by mastocytic differentiation in advanced myeloid neoplasms without evidence of SM. The group also proposes that MCL be divided into acute MCL and chronic MCL, based on the presence or absence of C-Findings. In addition, a primary (de novo) form of MCL should be separated from secondary MCL that typically develops in the presence of a known antecedent MC neoplasm, usually aggressive SM (ASM) or MC sarcoma. For MCL, an imminent prephase is also proposed. This prephase represents ASM with rapid progression and 5%-19% MCs in BM smears, which is generally accepted to be of prognostic significance. We recommend that this condition be termed ASM in transformation to MCL (ASM-t). The refined classification of MCL fits within and extends the current WHO classification; and should improve prognostication and patient selection in practice as well as in clinical trials.
肥大细胞白血病（MCL）是系统性肥大细胞增多症（SM）的白血病表现形式，其特征为未成熟肥大细胞（MCs）在骨髓（BM）和其他内脏器官中呈白血病样增殖，且预后较差。在一部分患者中，可检测到循环中的MCs。MCL的主要鉴别诊断是髓系肥大细胞白血病（MML）。尽管已公布了MCL和MML的诊断标准，但在术语和亚型方面仍存在一些问题。为了讨论这些未解决的问题，欧盟/美国共识小组和欧洲肥大细胞增多症能力网络（ECNM）在2011 - 2013年发起了一系列会议和研讨会。本文提供了由此产生的讨论和结果。该小组建议将MML视为一种独特的疾病，定义为晚期髓系肿瘤中的肥大细胞分化，且无SM证据。该小组还提议根据是否存在C发现将MCL分为急性MCL和慢性MCL。此外，原发性（新发）MCL应与继发性MCL区分开来，继发性MCL通常在已知的先行MC肿瘤存在的情况下发生，通常是侵袭性SM（ASM）或MC肉瘤。对于MCL，还提出了一个即将发生的前期阶段。这个前期阶段表现为ASM且进展迅速，骨髓涂片中有5% - 19%的MCs，一般认为具有预后意义。我们建议将这种情况称为转化为MCL的ASM（ASM - t）。MCL的细化分类符合并扩展了当前的世界卫生组织分类；并且在实践以及临床试验中应能改善预后评估和患者选择。
