INTRODUCTION
Primary effusion lymphoma (PEL) is a rare aggressive B-cell neoplasm that presents with serous malignant effusions without detectable tumor associated mass.1 It is related with HHV8 infection and mainly affects immunocompromised patients such as HIV-infected individuals, recipients of solid-organ transplantation or elderly patients.3 Moreover, the coinfection with Epstein-Barr virus (EBV) is frequent. The term “primary effusion lymphoma” was first described in the literature in 1996 by Nador et al.3 to define malignant lymphomatous effusions related to HHV8 infection. In 2001, the World Health Organization (WHO) introduced the category of PEL only for HHV8-related primary lymphomatous effusions. In 1996 Hermine et al.4reported the first HHV8 negative lymphomatous effusion in an HIV-seronegative patient. Since then, more than 60 HHV8-unrelated effusion-based lymphomas (EBL) have been reported in the literature, most of them in Japan, and terms as EBL and PEL-like lymphomas have been used. Recently, the ICC of Mature Lymphoid Neoplasms has recognized these cases as a new provisional entity named HHV8 and EBV-negative primary effusion-based lymphoma.2 Moreover, WHO Classification, 5th edition, has also recently recognized this entity as fluid overload-associated large B-cell lymphoma.5
We report a 72-year-old patient that presented with pericardial effusion with no evidence of tumor mass. Morphologic, immunophenotypic and molecular studies of the tumor cells of the pericardial effusion were performed. Cytological analysis showed large cells with irregular nuclei, prominent nucleoli and vacuolized cytoplasm. Immunophenotype showed expression of CD45, CD19, CD20 without detection of surface immunoglobulin. The tumor cells were negative for LANA-1 and EBER. Finally, PEL-like was diagnosed. To date, clinical and pathologic features of HHV8-unrelated, effusion-based lymphomas (EBL) are poorly understood. We report herein a case of the new entity HHV8- and EBV-negative primary effusion-based lymphoma, presenting in a Caucasian woman and review the literature.