Qiu, Lianqun

Abstract The diagnosis of T‐cell neoplasms remains one of the most challenging areas in hematopathology due to the immunophenotypic heterogeneity and subtle aberrancies often present in these entities. This “Best Practice” manuscript provides a practical framework for laboratories to design, validate, and interpret immunophenotyping studies of immature and mature T‐cell neoplasms. We outline the utility of key antigens in the screening and classification of T‐cell lymphomas/leukemia including TRBC1 and TRBC2. Analytical strategies using the “difference from normal” method and template‐based gating are discussed, along with validation considerations aligned with CLSI H62 guidelines. By integrating these principles into laboratory workflows, this manuscript aims to standardize and improve the assessment of T‐cell neoplasms across diverse clinical settings.