Polymerase chain reaction (PCR) assays have been developed for follicular lymphoma-associated BCL-2/J(H) translocations. Few data are available on the quantitation by PCR of these translocations in peripheral blood mononuclear cells (PBM) of follicular lymphoma (FL) patients. We report that only one of five studied FL patients had a high level of these translocations in the circulation, namely, about 35,000 translocations per 5 x 10(6) PBM. This patient was stable with an excellent performance status at the time of this assay; however, he died of leukemia 1 month later.