Hasserjian Robert P, Orazi Attilio, Orfao Alberto, Rozman Maria, Wang Sa A
Department of Pathology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Warren 244, Boston, MA, 02114, USA.
Department of Pathology, Texas Tech University Health Sciences Center, El Paso, TX, USA.
Virchows Arch. 2023 Jan;482(1):39-51. doi: 10.1007/s00428-022-03417-1.
The International Consensus Classification (ICC) of myeloid neoplasms and acute leukemia has updated the classification of myelodysplastic syndromes (MDSs) and placed MDS in a broader group of clonal cytopenias that includes clonal cytopenia of undetermined significance (CCUS) and related entities. Although subject to some interobserver variability and lack of specificity, morphologic dysplasia remains the main feature that distinguishes MDS from other clonal cytopenias and defines MDS as a hematologic malignancy. The ICC has introduced some changes in the definition of MDS whereby some cases categorized as MDS based on cytogenetic abnormalities are now classified as CCUS, while SF3B1 and multi-hit TP53 mutations are now considered to be MDS-defining in a cytopenic patient. The ICC has also recognized several cytogenetic and molecular abnormalities that reclassify some cases of MDS with excess blasts as acute myeloid leukemia (AML) and has introduced a new MDS/AML entity that encompasses cases with 10-19% blasts that lie on the continuum between MDS and AML. Two new genetically defined categories of MDS have been introduced: MDS with mutated SF3B1 and MDS with mutated TP53, the latter requiring bi-allelic aberrations in the TP53 gene. The entity MDS, unclassifiable has been eliminated. These changes have resulted in an overall simplification of the MDS classification scheme from 8 separate entities (including 1 that was genetically defined) in the revised 4th edition WHO classification to 7 separate entities (including 3 that are genetically defined) in the ICC.
髓系肿瘤和急性白血病的国际共识分类（ICC）更新了骨髓增生异常综合征（MDS）的分类，并将MDS归为更广泛的一组克隆性血细胞减少症，其中包括意义未明的克隆性血细胞减少症（CCUS）及相关实体。尽管存在一定的观察者间差异且缺乏特异性，但形态学发育异常仍是区分MDS与其他克隆性血细胞减少症的主要特征，并将MDS定义为一种血液系统恶性肿瘤。ICC在MDS的定义上引入了一些变化，据此，一些基于细胞遗传学异常被归类为MDS的病例现在被分类为CCUS，而SF3B1和多打击TP53突变现在被认为在血细胞减少的患者中可定义MDS。ICC还认识到一些细胞遗传学和分子异常，这些异常将一些伴原始细胞增多的MDS病例重新分类为急性髓系白血病（AML），并引入了一个新的MDS/AML实体类别，其中包括原始细胞比例为10%-19%、处于MDS和AML之间连续状态的病例。引入了两个新的基于遗传学定义的MDS类别：伴有SF3B1突变的MDS和伴有TP53突变的MDS，后者要求TP53基因存在双等位基因畸变。无法分类的MDS实体类别已被取消。这些变化使得MDS分类方案从世界卫生组织（WHO）修订的第4版分类中的8个独立实体（包括1个基于遗传学定义的实体）总体简化为ICC中的7个独立实体（包括3个基于遗传学定义的实体）。
