Flow cytometric analysis of lymphoma and lymphoma-like disorders.

The use of flow cytometry (FC) represents the most recent advance in the phenotypic analysis of lymphocyte subsets, and has emerged as a valuable adjunct in the diagnosis of malignant non-Hodgkin's lymphoma (NHL). In a review of over 200 cases of nodal and extranodal suspected lymphomas studied in the Immunophenotyping Laboratory at the University of New Mexico, the diagnostic utility of FC was assessed. Among cases of NHL, FC was able to confirm a morphologic diagnosis of lymphoma and determine B or T cell lineage in greater than 85% of the samples submitted. Difficulty in lineage determination in the remaining cases of morphologic NHL was multifactorial. Among cases of reactive lymph nodes and Hodgkin's disease, FC showed no characteristic patterns, although several cases exhibited phenotypic profiles suggestive of B or T cell clonality. When combined with routine morphologic review and accompanied by other specialized diagnostic techniques when necessary, the use of FC represents a precise and reproducible method for rapidly and easily studying lymphoproliferative disorders in solid tissue.