[Chinese expert consensus on the application of flow cytometry in the diagnosis and detection of minimal residual disease in B-cell non-Hodgkin lymphoma (2025)].

B-cell non-Hodgkin lymphoma (B-NHL) is made up of multiple subtypes, whose precise diagnosis relies on multidisciplinary collaboration, including pathological morphology, immunohistochemistry, flow cytometry (FCM), cytogenetics, molecular biology, imaging and clinical features. FCM plays an irreplaceable role in the diagnosis of B-NHL and minimal/measurable residual disease (MRD) monitoring due to its unique advantages of simplicity, rapidness, objectivity, high sensitivity, and multi-parameter analysis. With the publication of the 5th edition of the World Health Organization (WHO) Classification of Haematolymphoid Tumours and the International Consensus Classification (ICC), the classification of B-NHL has become more refined, with significant changes in some classification methods and nomenclature. To improve the diagnostic and therapeutic monitoring ability of B-NHL and standardize the diagnosis and treatment procedures of B-NHL in China, the Hematological Oncology Committee of the China Anti-Cancer Association organized relevant domestic experts to develop this expert consensus after multiple discussions. The consensus focuses on the application of FCM in the diagnosis and MRD detection of mature B-NHL including the sources and preparation of samples for FCM, the immunophenotypic characteristics of different subclasses of B-NHL, result analysis and reporting, and quality control.