Hurwitz C A, Mirro J
Department of Hematology/Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee.
Hematol Oncol Clin North Am. 1990 Aug;4(4):767-94.
Considerable confusion exists regarding the definition of acute mixed-lineage leukemia. We have proposed a list of strict criteria, limiting the term acute mixed-lineage leukemia to those patients whose blast cells co-express lymphoid and myeloid characteristics. This system includes cytochemical, immunologic, molecular, and cytogenetic characteristics that are strongly associated with either lymphoid or myeloid lineages. As more information becomes available, the criteria for mixed-lineage leukemia will undoubtedly change. Identification of patients with mixed-lineage leukemia and metachronous leukemia (lineage switch) is important for determining the prognostic implications of these findings. Care must be taken in identifying cases of metachronous leukemia because of the increased incidence of second malignancies following aggressive therapy. Evidence of a recurrence of the original clone must be obtained before metachronous leukemia can be diagnosed. As with mixed-lineage and metachronous leukemias, the potential clinical and prognostic implications of lymphoid leukemias with antigenic asynchrony should be identified. The asynchronous antigen expression in leukemic lymphoblasts may provide a means for detecting minimal residual disease. Detection of minimal residual leukemia is possible because these blasts differ from the predominant population of normal lymphoid cells in their expression of cell surface markers. Study of the mechanisms that lead to these unusual leukemias may result in better understanding of the processes that underlie both normal hematopoietic differentiation and leukemogenesis. An understanding of these leukemias may also permit identification of cases that are destined to fail current therapies so that more intensive or selective therapy can be instituted for such children. Curing the 30% of children with ALL that relapse despite our best efforts should be one of the top priorities for pediatric oncologists.
关于急性混合谱系白血病的定义存在相当大的混淆。我们提出了一系列严格的标准，将急性混合谱系白血病这一术语限定于那些原始细胞同时表达淋巴样和髓样特征的患者。该系统包括与淋巴样或髓样谱系密切相关的细胞化学、免疫学、分子和细胞遗传学特征。随着更多信息的获得，混合谱系白血病的标准无疑将会改变。识别混合谱系白血病和异时性白血病（谱系转换）患者对于确定这些发现的预后意义很重要。由于积极治疗后第二原发恶性肿瘤的发生率增加，在识别异时性白血病病例时必须谨慎。在诊断异时性白血病之前，必须获得原始克隆复发的证据。与混合谱系和异时性白血病一样，应确定具有抗原异步性的淋巴样白血病的潜在临床和预后意义。白血病淋巴母细胞中的异步抗原表达可能为检测微小残留病提供一种手段。检测微小残留白血病是可能的，因为这些母细胞在细胞表面标志物的表达上与正常淋巴样细胞的主要群体不同。对导致这些特殊白血病的机制进行研究可能会更好地理解正常造血分化和白血病发生的基础过程。对这些白血病的了解还可能有助于识别那些注定对当前治疗无效的病例，以便为这些儿童制定更强化或更具选择性的治疗方案。尽管我们尽了最大努力，但仍有30%的急性淋巴细胞白血病儿童复发，治愈这些儿童应是儿科肿瘤学家的首要任务之一。
