Analytical appraisal of hematogones in B-ALL MRD assessment using multidimensional dot-plots by multiparametric flow cytometry: A critical review and update

Abstract

The spectrum of benign B-cell precursors, known as hematogones (HGs), shows a significant morphological and immunophenotypic overlap with their malignant counterpart i.e. B-lymphoid blasts (BLBs). This results in a diagnostic dilemma in assessment of cases wherein there is a physiological preponderance of HGs and also poses a significant challenge in measurable residual disease assessment in B-cell acute lymphoblastic leukaemia. Consequently, expression patterns of various immunophenotypic markers are considered the most important tool in identification and delineation of HGs from BLBs. However, certain aspects of B-cell compartment evaluation by flow cytometric immunophenotyping and its relevance in clinical scenarios is yet to be defined precisely. This review summarizes current flowcytometric data on HGs and its discrimination from BLBs based on thorough review of literature and evaluation of in-house data. Furthermore, it focuses on the utility of an additional analytical tool i.e., radar plot for a comprehensive representation of various subsets of the B-cell compartment and their differentiation from BLBs.