Utility of Flow Cytometry in Diagnosis of Lymphomas from Tissue Samples

The accurate early diagnosis of lymphomas is crucial for effective treatment. In aggressive variants, a delay in diagnosis may lead to a poorer clinical outcome. Although flow cytometry (FC) provides a rapid and detailed analysis of cell populations, immunohistochemistry (IHC), in conjunction with histopathology (HP), remains the gold standard for diagnosis. The purpose of this study was to compare the results of the standard histopathological method with the accuracy of FC performed on lymph node tissue in the diagnosis of lymphoma. Between August 2022 and July 2024, we enrolled 43 patients who were clinically suspected of having lymphoma in a prospective study. Each removed lymph node was split into two parts: one underwent traditional HP and IHC, and the other was assessed by FC using case-appropriate antibody panels. For both approaches, we computed sensitivity, specificity, and turnaround time (TAT) in addition to assessing diagnostic accuracy. With an 84.8% concordance rate, FC showed a high degree of accuracy with HP in non-Hodgkin lymphoma cases. Overall, the specificity was 80% and the sensitivity was 83.3%. With a median TAT of roughly two days, FC results are available earlier than HP results, which take almost six days (p < 0.0001). Rapid clinical decisions and treatment initiation were made possible by the earlier reporting. FC cannot replace tissue architecture assessment. However, it provides meaningful, quick, and supportive diagnostic information. Its shorter reporting time and good accuracy make it especially useful in urgent clinical situations or in labs with limited resources.