摘要意义未明特发性血细胞减少症(ICUS)是指持续时间≥4个月的一系或多系血细胞减少，不符合骨髓增生异常综合征(MDS)的最低诊断标准，并且不能归类于任何其他血液或非血液系统疾病的一类疾病的总称。随着二代测序(NGS)技术的发展，部分ICUS患者可被鉴别诊断为意义不明的克隆性血细胞减少症(CCUS)，其具有克隆性造血等与早期MDS相似的临床特征。大部分ICUS患者病程呈惰性，部分患者可进展为MDS、急性髓细胞白血病(AML)等髓系肿瘤。笔者通过对ICUS及CCUS的定义、发病机制、预后与随访管理等方面研究现状进行阐述，旨在对ICUS患者的临床诊断、鉴别诊断和预后评估提供理论依据。

abstractsIdiopathic cytopenia of undetermined significance (ICUS) refers to a class of diseases with primary or multiple lineage cytopenia, lasting for 4 months or more, but does not meet the minimum diagnostic criteria of myelodysplastic syndrome(MDS), and can not be attributed to any other hematology or other diseases. With the development of next generation sequencing (NGS) technology, some patients with ICUS have been identified as clonal cytopenia of unknown significance (CCUS), who have clinical characteristics similar to early MDS, such as clonal hematopoiesis. Most ICUS patients have an inert course. Some ICUS patients may progress to myeloid tumors such as MDS and acute myeloid leukemia (AML). This article expounds the research status of ICUS and CCUS, such as definition, pathogenesis, prognosis and follow-up management, aiming to provide theoretical basis for clinical diagnosis, differential diagnosis and prognosis evaluation of ICUS patients.