国际共识分类（ICC）和世界卫生组织分类第五版（WHO-5）对髓系肿瘤的分类进行了实质性更新。本研究比较了一系列原始细胞增多的骨髓肿瘤的系统，分析了对诊断工作流程和报告的影响。根据 WHO-R4 分类为原始细胞增多的骨髓增生异常综合征 (MDS-EB) 或急性髓系白血病 (AML) 的骨髓活检是确定。汇编了形态学检查、核型、荧光原位杂交和下一代测序的结果。 WHO-5和ICC对病例进行回顾性重新分类。对46例病例进行了审查。 28 例 (61%) 的原始细胞≥20%，其余病例的原始细胞为 5-19.5%。分类中最常见的差异是 1) 对于原始细胞为 10-19% 的病例，MDS 与 MDS/AML 的指定（10/46，22%）和 2) ICC 将 TP53 变体指定为 AML 的单独分类器（8 /46, 17%）。在 15 例 (33%) 病例中发现了双等位基因/多重命中 TP53 改变。在 29 (63%) 例病例中鉴定出具有潜在种系意义的变异。虽然 WHO-5 和 ICC 之间存在术语差异，但两个系统都利用类似的机会来改进报告：致病性变异的标准化分类（特别是 TP53）、简化的系统来评估潜在的种系变异，以及形态学和遗传数据的综合报告。版权所有 © 2024。由 Elsevier Inc. 出版。

The International Consensus Classification (ICC) and 5th Edition of the World Health Organization Classification (WHO-5) made substantive updates to the classification of myeloid neoplasms. This study compares the systems in a series of myeloid neoplasms with increased blasts, analyzing implications for diagnostic workflow and reporting.Bone marrow biopsies categorized as myelodysplastic syndrome with excess blasts (MDS-EB) or acute myeloid leukemia (AML) by WHO-R4 were identified. Results of morphology review, karyotype, fluorescence in situ hybridization, and next-generation sequencing were compiled. Cases were retrospectively re-classified by WHO-5 and ICC.46 cases were reviewed. 28 cases (61 %) had ≥20 % blasts, with the remaining cases having 5-19.5 % blasts. The most common differences in classification were 1) the designation of MDS versus MDS/AML (10/46, 22 %) for cases with 10-19 % blasts and 2) the ICC's designation of TP53 variants as a separate classifier for AML (8/46, 17 %). Bi-allelic/multi-hit TP53 alterations were identified in 15 cases (33 %). Variants of potential germline significance were identified in 29 (63 %) cases.While terminology differences between WHO-5 and ICC exist, both systems invoke similar opportunities for improved reporting: standardized classification of pathogenic variants (notably TP53), streamlined systems to evaluate for potential germline variants, and integrated reporting of morphologic and genetic data.Copyright © 2024. Published by Elsevier Inc.