Flow cytometry has been used to evaluate patients with L&L for more than 35 years but assessing its future requires a critical assessment of its Strengths, Weaknesses, Opportunities and Threats. 

Flow is a robust, well-established technique that has become the gold standard for classifying L&L, and is in widespread use in all centers that diagnosis and treat patients with these diseases.  Its rapidity makes it an ideal tool to guide clinicians confronted with a patient needing immediate therapy.  Flow monitoring to measure minimal residual disease provides both prognostic information and also directs subsequent therapy in nearly all types of L&L.  However, the technology has been held back by the variability of approaches used, in large part driven by the expertise required for analysis, making people reluctant to switch from approaches with which they are familiar.  Recent years have seen significant if incomplete progress standardizing antibody panels and improving inter-laboratory agreement, but standardizing analysis has been a more difficult challenge.  Robust L&L analytics, particularly ones immune to slight changes in cellular properties attendant upon real-world situations, will be important to advance the field.  The field also must look to leverage biological discoveries in L&L to develop new assays.  Some promising starts have been made, but much development works needs to be done.  Threats to flow include diversion of available laboratory resources to genomic analysis both for classification and ultimately monitoring of L&L patients as is already happening with high throughput sequencing of antigen receptors as an assay for MRD monitoring of lymphoid malignances.