Classic KSHV/HHV-8-positive Primary Effusion Lymphoma (PEL): A Systematic Review and Meta-Analysis of Case Reports

Abstract

Primary effusion lymphoma (PEL) is a large B-cell lymphoma growing within body-cavities caused by the Kaposi sarcoma-associated herpesvirus (KSHV)/human herpesvirus-8 (KSHV/HHV-8). It is mainly reported in HIV-infected patients. The uncommon occurrence in the elderly supports a form paralleling classic Kaposi sarcoma (KS), i.e. classic PEL, whose characteristics are relatively underexplored. To better understand the diagnostic modalities and clinical-epidemiological features of classic PEL, articles reporting cases of PEL were identified through MEDLINE/EMBASE databases (January 1998-July 2020) and screened according to PRISMA guidelines to extract individual-level data. A comparison was also performed between classic PEL and classic KS to evaluate similarities and differences. We identified 105 subjects (median age 77 years; 86% males), mainly from Mediterranean countries (52%, first Italy) and Eastern Europe (7%). Common comorbidities were heart failure (32%), cirrhosis (16%), and malignancy (20%) including lymphoid neoplasms. Pleural cavity was the commonest site (67%). PEL diagnosis was based on cytomorphology (89%), evidence of KSHV/HHV-8 infection (94%), EBV co-infection (28%) and clonality of IGH (59%), IGK (14%), TRG (9%) alone or in multiple combinations. Compared to KS, age (P