摘要目的:探讨儿童急性前B淋巴细胞白血病伴 C- MYC重排(preBLL)患儿的病例特点、诊断归类及治疗方法。 方法:对首都儿科研究所附属儿童医院血液科2019年6月和9月分别收治的2例preBLL患儿的临床及实验室资料进行分析。结果:2例患儿均为儿童急性淋巴细胞白血病，临床上肝脾大显著，末梢白细胞均明显升高，骨髓形态学为L3，细胞免疫表型为前B细胞表型，细胞遗传学检测可见 C- MYC重排。2例患儿均接受成熟B细胞肿瘤方案(FAB/LMB96)治疗，1例伴 TP53基因突变的患儿病情先缓解后又复发死亡，另1例患儿治疗后病情保持持续缓解。 结论:preBLL患儿临床较罕见，应对形态学为L3的前B细胞白血病患儿进行常规 C- MYC重排检测。其治疗方法尚需进一步研究，应积极开展多中心临床研究，对此类病例进行大样本的分析和总结，寻找有效治疗方案，提升患儿存活率。

abstractsObjective:To explore the characteristics, diagnosis, and treatment of precursor B-cell acute lymphocytic leukemia with C- MYC rearrangement (preBLL) in children. Methods:The clinical data in 2 cases of childhood preBLL in Department of Hematology, Children′s Hospital Affiliated to Capital Institute of Pediatrics in June and August 2019 were summarized and analyzed.Results:Both cases were acute lymphoblastic leukemia with precursor B-cell immunophenotype.Hepatosplenomegaly and peripheral white blood cells were significantly increased, and the morphology of bone marrow was L3. C- MYC rearrangement was discovered by cytogenetic tests.Both children have received the treatment of the mature B-cell tumor protocol (FAB/LMB96), and early remission was developed in 1 case with TP53 gene mutation but relapsed thereafter and died finally.Another case had reached sustained complete remission after treatment. Conclusions:Children with preBLL is rare, and routine C- MYC rearrangement should be performed in children with Precursor B-cell lymphoblastic leukemia whose morphology of bone marrow was L3.Its treatment needs to be further studied, and multi-center clinical trials need to be actively conducted to analyze and summarize large numbers of cases to identify effective protocol and improve the prognosis.