摘要目的:探讨儿童获得性再生障碍性贫血（acquired aplastic anemia，AAA）和儿童难治性血细胞减少（refractory cytopenia of childhood，RCC）的骨髓组织病理学区别，为诊断和鉴别诊断这两种疾病提供理论依据。方法:收集2008年1月至2018年12月在上海交通大学医学院附属新华医院和上海交通大学医学院附属上海儿童医学中心首诊AAA和RCC的病例，回顾性分析其临床资料和骨髓活检结果。结果:收集150例患儿资料，71例AAA和79例RCC；AAA组中男性52例，女性19例，年龄范围1.0~15.0岁（中位数8.9岁）；RCC组中男性53例，女性26例，年龄范围0.5~16.0岁（中位数5.0岁）。AAA骨髓活检示增生极其低下，88.7%（63/71）骨髓造血细胞比例<5%，11.3%（8/71）在5%~24%，且无1例见病态造血。RCC骨髓活检示增生低下，94.9%（75/79）骨髓造血细胞比例在5%~50%，所有病例均见片灶性造血，40.5%（32/79）见红系病态造血，60.8%（48/79）见小巨核细胞。结论:造血细胞增生低下程度、造血细胞分布方式、红系造血岛细胞成分及其定位和发育不良巨核细胞的出现可帮助两者进行诊断和鉴别诊断。

abstractsObjective:To study the differences in the bone marrow histopathology between acquired aplastic anemia (AAA) in children and refractory cytopenia of childhood (RCC) to facilitate their diagnoses and differential diagnosis.Methods:The clinical data and bone marrow biopsies of the RCC and AAA cases diagnosed from January 2008 to December 2018 in Xinhua Hospital, Shanghai Jiaotong University School of Medicine and Shanghai Children′s Medical Center affiliated to Shanghai Jiaotong University School of Medicine were analyzed.Results:A total of 71 AAA and 79 RCC cases were analyzed. There were 52 males and 19 females, age ranged 1.0-15.0 years (median, 8.9 years) in the AAA group, and 53 males and 26 females, age ranged 0.5-16.0 years (median, 5.0 years) in the RCC group. All the biopsy specimens of AAA patients had severe hypocellularity; the cellularity of 88.7% (63/71) specimens was under 5.0%, and 11.3%(8/71) was 5%-24%. None of the AAA specimens showed any dysplastic change. All the biopsy specimens of RCC patients had hypocellularity, including 94.9%(75/79) of the specimens with a cellularity of 5%-50%. All of the RCC specimens showed a patchy distribution of hematopoiesis. A dysplastic change of erythroid cells and micromegakaryocytes was found in 40.5% (32/79) and in 60.8% (48/79) of the RCC cases, respectively.Conclusions:The degree of hypocellularity, the distribution pattern of hematopoiesis, the cell composition and localization of erythroid cell clusters and the appearance of micromegaryocytes could help the diagnosis and differential diagnosis of AAA and RCC.