Kaposi's sarcoma-associated herpesvirus in non-AIDS related lymphomas occurring in body cavities

DNA sequences belonging to the recently discovered Kaposi's sarcoma-associated herpesvirus (KSHV), now provisionally designated human herpesvirus 8, have been previously identified in an uncommonly occurring subset of AIDS-related lymphomas, referred to as body-cavity-based lymphomas (BCBLs), which present as lymphomatous effusions. Pyothorax-associated lymphomas (PALS) are non-Hodgkin's lymphomas that arise in the pleural cavity after long-standing pleural inflammation resulting from therapeutic artificial pneumothorax or from tuberculosis pleuritis. Although PALs present as solid tumor masses, they are otherwise similar to BCBLs in that they also are B cell lymphomas, usually exhibit immunoblastic morphology, and contain Epstein-Barr virus. We investigated whether KSHV sequences are present in 2 BCBLs in patients without AIDS and 12 in Japanese and 2 French PALs. The 2 BCBLs were positive for KSHV sequences, whereaas all 14 PALs were KSHV negative. This finding strongly suggests that BCBLs and PALs are distinct clinicopathological entities and further strengthens the association between the presence of KSHV and an effusion phenotype. Based on these findings, we propose replacing the term body-cavity-based lymphoma with the term primary effusion lymphoma, which describes these non-Hodgkin's lymphomas more accurately and avoids confusion with other lymphomas that may occur in the body cavities, such as the PALs.