Monoclonality in reactive lymphadenopathy: gene rearrangement and multiparameter analysis.

Multiparameter analysis of lymph nodes with follicular, interfollicular, and/or atypical hyperplasia was undertaken to search for monoclonality. Twenty-three patients aged 7 to 75 years (mean 32 years) were studied. One patient had a history of lymphoma; two were HIV-positive. Nodes were removed for clinical suspicion of lymphoma. Light microscopy revealed increased and&or abnormal follicular proliferation and occasional progressive transformation of germinal centers. Immunostaining of frozen sections revealed CD4, CD8, kappa, and lambda positivity with more CD4+ than CD8+ cells. Flow cytometry showed a mixed population of T and B cells with no evidence of clonality. Hybridization studies with JH and JK probes showed rearranged bands in one case. No rearrangements were seen with CT beta and bcl-2 probes. Follow-up of 3 to 5 years showed no new occurrences of lymphoma. Although no evidence of monoclonality was seen with other parameters, DNA hybridization revealed heavy and light chain gene rearrangement in 4% (1 of 23).