A Unique Case of Malignant Pleuropericardial Effusion: HHV-8-Unrelated PEL-Like Lymphoma—A Case Report and Review of the Literature

Abstract

Primary effusion lymphoma (PEL) or body cavity lymphoma is a rare type of extra nodal lymphoma of B-cell origin that presents as lymphomatous effusion(s) without any nodal enlargement or tumor masses. It belongs to the group of AIDS related non-Hodgkin's lymphomas. First described in 1996 in HIV infected individuals who were coinfected with Kaposi's sarcoma-associated herpesvirus (KSHV) or HHV-8 virus, it was included as a separate entity in WHO classification of tumors of hematopoietic and lymphoid tissue in the year 2001. The definition included association with HHV-8 virus as a mandatory diagnostic criterion. However, cases were later reported where PEL-like disease process was diagnosed in HHV-8 negative patients. This was eventually recognized as a rare but distinct entity termed as “HHV-8-unrelated PEL-like lymphoma”. Herein, we are reporting a case of an elderly patient who presented with a large pleuropericardial effusion and was eventually diagnosed with this entity. Till date, only around 50 cases of HHV-8-unrelated PEL-like lymphoma have been reported and our case being EBV, HIV, and Hepatitis C negative makes it very unique and rare occurrence. We are also presenting a review of relevant literature focused mainly on comparing outcomes in patients treated with and without chemotherapy.

Primary effusion lymphoma in Taiwan shows two distinctive clinicopathological subtypes with rare human immunodeficiency virus association

“…Using this simple criterion based on HHV8 association, we reviewed the literature cases and separated the previously reported and our current cases (total cases: 256) as either classical (type 1) PEL or type II PEL (or EBL). 6,7,12,16,19,22,[24][25][26][27]38 As listed in Tables 3 and 4, the ratio of type I to type II PEL was 2:1. Compared to type II PEL, type I PEL was associated more frequently with HIV and EBV infection (both P < 0.001), while MYC rearrangement was less frequent than type II PEL (3% versus 29%; P = 0.004; Table 5).…”

“…In the literature, the terms ‘PEL’ and ‘EBL’ are somewhat confusing in use, and sometimes these names seem to have been used interchangeably. Some HHV8‐negative cases have been reported as PEL . As the term ‘primary effusion lymphoma’ is self‐explanatory and is easy to understand, while the term ‘effusion‐based lymphoma’ is a little obscure and is not readily distinct from PEL, we propose to call the HHV8‐positive cases ‘classical’ or ‘type I PEL’ and the HHV8‐negative cases ‘type II PEL’, stressing the similarities between these two groups, although there is an immunophenotypical difference.…”

“…Some HHV8-negative cases have been reported as PEL. 7,11,12,14,16,23,26,27,37 As the term 'primary effusion lymphoma' is self-explanatory and is easy to understand, while the term 'effusion-based lymphoma' is a little obscure and is not readily distinct from PEL, we propose to call the HHV8-positive cases 'classical' or 'type I PEL' and the HHV8-negative cases 'type II PEL', stressing the similarities between these two groups, although there is an immunophenotypical difference. Using this simple criterion based on HHV8 association, we reviewed the literature cases and separated the previously reported and our current cases (total cases: 256) as either classical (type 1) PEL or type II PEL (or EBL).…”

A unique case of primary effusion lymphoma‐like lymphoma showing disappearance and recurrence of the body cavity effusion

“…To date, few papers have investigated the clinical features and the treatment of PEL‐LL patients who are generally elderly, express CD20 for pan‐B‐cell antigens, and have a slow prognosis for mortality 5, 6. PEL has a strong prognosis for mortality during the early phase, whereas the literature includes numerous reports of favorable responses to chemotherapy in patients with PEL‐LL 7.…”

Lymphoproliferative disorder in pleural effusion in a subject with past asbestos exposure

“…Those cases are considered a rare disease entity called HHV8-unrelated PEL-like lymphoma [3] . Advanced age [4] remains the only known risk factor for PEL-like lymphoma, and the pathogenic mechanisms remain unclear. It has been reported that patients with HHV8-unrelated PEL-like lymphoma show better outcomes than patients with PEL [5] .…”