A Retrospective Study of Cases Analyzed by Flow Cytometry

A b s t r a c t Flow cytometric analysis is important in the diagnosis, classification, and follow-up of non-Hodgkin lymphoma. It is assumed that the lymphoma phenotype for each patient remains unchanged over time and is consistent from one specimen to another. To determine the variability in expression of lymphoid antigens, we reviewed 211 flow cytometry specimens of malignant lymphoma from 81 patients. Some antigens showed a stable pattern of expression such as CD5, CD10, CD19, CD20, and HLA-DR. In contrast, CD21, CD22, CD23, and CD25 showed more variability from one specimen to another. We believe several factors affect the stability of antigen expression. True differences in expression most probably are related to the biology and function o