Department of Pathology, University of Chicago, Chicago, IL 60637, USA.
Hematology Am Soc Hematol Educ Program. 2011;2011:250-6. doi: 10.1182/asheducation-2011.1.250.
There is no single category in the fourth edition (2008) of the World Health Organization (WHO) classification of myeloid neoplasms that encompasses all of the diseases referred to by some authors as the myeloproliferative neoplasm (MPN) "variants." Instead, they are considered as distinct entities and are distributed among various subgroups of myeloid neoplasms in the classification scheme. These relatively uncommon neoplasms do not meet the criteria for any so-called "classical" MPN (chronic myelogenous leukemia, polycythemia vera, primary myelofibrosis, or essential thrombocythemia) and, although some exhibit myelodysplasia, none meets the criteria for any myelodysplastic syndrome (MDS). They are a diverse group of neoplasms ranging from fairly well-characterized disorders such as chronic myelomonocytic leukemia to rare and thus poorly characterized disorders such as chronic neutrophilic leukemia. Recently, however, there has been a surge of information regarding the genetic infrastructure of neoplastic cells in the MPN variants, allowing some to be molecularly defined. Nevertheless, in most cases, correlation of clinical, genetic, and morphologic findings is required for diagnosis and classification. The fourth edition of the WHO classification provides a framework to incorporate those neoplasms in which a genetic abnormality is a major defining criterion of the disease, such as those associated with eosinophilia and abnormalities of PDGFRA, PDGFRB, and FGFR1, as well as for those in which no specific genetic defect has yet been discovered and which remain clinically and pathologically defined. An understanding of the clinical, morphologic, and genetic features of the MPN variants will facilitate their diagnosis.
在第四版（2008 年）世界卫生组织（WHO）髓系肿瘤分类中，没有一个类别包含一些作者所提到的所有疾病，即所谓的“骨髓增殖性肿瘤（MPN）‘变体’”。相反，它们被视为不同的实体，并分布在分类方案中的各种髓系肿瘤亚组中。这些相对罕见的肿瘤不符合任何所谓的“经典”MPN（慢性髓性白血病、真性红细胞增多症、原发性骨髓纤维化或特发性血小板增多症）的标准，虽然有些表现出骨髓增生异常，但没有一个符合任何骨髓增生异常综合征（MDS）的标准。它们是一组多样化的肿瘤，从相当明确的疾病，如慢性髓单核细胞白血病，到罕见且因此特征较差的疾病，如慢性中性粒细胞白血病。然而，最近，关于 MPN 变体中肿瘤细胞的遗传结构的信息大量涌现，使得一些能够在分子水平上定义。然而，在大多数情况下，需要对临床、遗传和形态学发现进行相关性分析，才能进行诊断和分类。第四版 WHO 分类为那些遗传异常是疾病主要定义标准的肿瘤提供了一个框架，例如与嗜酸粒细胞增多和 PDGFRA、PDGFRB 和 FGFR1 异常相关的肿瘤，以及那些尚未发现特定遗传缺陷且仍在临床上和病理上定义的肿瘤。了解 MPN 变体的临床、形态和遗传特征将有助于其诊断。
