Effusions revealed monocyte/macrophage-rich infiltration (10 patients) or large-cell lymphoma with CD45(+)/non-T/non-B phenotype (three of 13 patients); polymerase chain reaction analysis showed the presence of HHV-8 sequences (nine of 13 patients), germline IgH (seven of 12 patients) or clonal IgH rearrangements (four of 12 patients), and rarely Epstein-Barr virus sequences (two of 12 patients).