IMMUNOTYPING OF LYMPHOMA BY FINE-NEEDLE ASPIRATION - A COMPARATIVE-STUDY OF CYTOSPIN PREPARATIONS AND FLOW-CYTOMETRY

Immunotyping is an essential adjunct to cytomorphology for the diagnos is of lymphoma by fine-needle aspiration (FNA). Two independent techni ques, cytospin preparations and flow cytometry, were used for immunoty ping studies on 71 patients with histologically confirmed non-Hodgkin' s lymphoma (63 B-cell lymphomas and 8 T-cell lymphomas). Diagnostic co ncordance between the two methods was obtained in 69 patients (97%). k appa,lambda, and CD3 (Leu-4) markers were routinely measured on all cy tospins, and additional markers were requested when indicated. The sta ndard panel measured by flow cytometry included 14 markers. In general , mean values of light-chain (kappa and lambda) immunoglobulins were c onsistently slightly higher by cytospin analysis than by flow cytometr y. Light-chain immunoglobulin ratios (kappa/lambda or lambda/kappa) ob tained by both methods proved to be reliable independent predictors of polyclonality or monoclonality. Correlation studies using the Spearma n rank coefficient revealed good concordance among values of kappa, al pha, CD3, and CD5 obtained by the two techniques, suggesting that subj ective quantitation by cytospins yields similar results to objective q uantitation by flow cytometry. Cytospin analysis and flow cytometry ap pear equally capable of immunotyping aspirated lymphoid samples reliab ly. The advantages of each method are discussed.