PYOTHORAX-ASSOCIATED LYMPHOMA - RELATIONSHIP WITH EPSTEIN-BARR-VIRUS,HUMAN HERPES VIRUS-8 AND BODY CAVITY-BASED HIGH-GRADE LYMPHOMAS

Pyothorax-associated lymphoma (PAL) is a newly-described entity develo ping several decades after artificial pneumothorax treatment for pulmo nary or pleural tuberculosis. It is known to be associated with Epstei n-Barr virus (EBV) with constant expression of the two latent membrane proteins: latent membrane protein (LMP)-1 and EBV-associated nuclear antigen (EBNA)-2. We are reporting three new cases of PAL. All of the tumours were of B-cell lineage and classified as large-cell diffuse ly mphomas according to the International Working Formulation for the Cla ssification of Lymphomas. The EBV genome was detected in two of the ca ses with LMP-1 and EBNA-2 expression. No EBV could be detected in the third case suggesting that different mechanisms may be involved in the pathogenesis of the disease. Body cavity-based high grade lymphomas ( BCBL) represent a new disease, developing mainly in human immunodefici ency virus (HIV) infected patients: the tumoural cells often contain b oth human herpes virus (HHV)-8 (or Kaposi's sarcoma herpes virus) and EBV genomes, suggesting that these viruses might co-operate in the pat hogenesis of the disease. The pleural location and the association of EBV have led to speculation that PAL could also be related to HHV-8 in fection. However, no HHV-8 genome could be detected in any of the 14 t ested cases already reported in the literature nor in the two cases we studied (one EBV-positive and one EBV-negative), suggesting that PAL and BCBL are two different entities.