Simultaneous Cytomorphologic and Multiparametric Flow Cytometric Analysis on Lymph Node Samples Is Faster Than and as Valid as Histopathologic Study to Diagnose Most Non-Hodgkin Lymphomas

We evaluated the validity and accuracy of cytomorphology and multiparametric flow cytometry (C-FCM) in diagnosing oncohematologic disease in 223 consecutive lymph node biopsy specimens from patients with lymphadenopathy, from 2004 to 2007. C-FCM and histopathologic studies were interpreted independently by hematologists and pathologists, respectively. C-FCM detected neoplastic disorders in 133 samples (59.6%): 92 non-Hodgkin lymphomas (NHLs; 41.3%), 21 Hodgkin lymphomas (HLs; 9.4%), 19 malignant nonhematologic neoplasms (8.5%), and 1 multiple myeloma (0.4%). Sensitivity and specificity were 87.25% and 95.95%, respectively. Positive predictive value and negative predictive value (NPV) were 97.74% and 78.89%, respectively. Sensitivity and NPV were 94.79% and 96.81% upon excluding HL and malignant nonhematologic neoplasms from the analysis. Of the 92 NHLs, 89 (97%) were categorized according to the 2001 World Health Organization classification of hematolymphoid neoplasms with a concordance of 87%. The C-FCM study was significantly faster than the histopathologic study. C-FCM has high sensitivity and specificity, allowing for a valid and reliable diagnosis, especially in NHLs and enabling their subclassification. C-FCM is faster than the histopathologic examination, allowing for therapeutic decisions to be made quickly. However, in the samples in which C-FCM cannot establish a diagnosis, histopathologic results are needed.