Human herpesvirus 8‑negative effusion‑based lymphoma with indolent clinical behavior in an elderly patient: A case report and literature review

Abstract

Primary effusion lymphoma (PEL) is a B-cell non-Hodgkin's lymphoma that is usually characterized by lymphomatous effusions in the body cavity without any detectable tumor masses. According to the World Health Organization (WHO) schema for tumor classification, PEL is defined by the presence of human herpesvirus 8 (HHV8) in malignant lymphoid cells. However, a subset of effusion-based B-cell lymphoma is not HHV8-positive and exhibits different clinicopathological characteristics. The 2017 WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues does not list HHV8-negative effusion-based lymphoma, which remains an underappreciated B-cell lymphoma, as an individual entity. The present study reports a case of this rare type of lymphoma with indolent clinical behavior in a 75-year-old male patient receiving only symptomatic treatment. Additionally, a review of similar cases reported in the English literature is presented.

Primary Effusion Lymphoma: A Timely Review on the Association with HIV, HHV8, and EBV

“…PEL has been reported in HIV and HHV8-negative elderly patients without immunodeficiency [10,19,20,38]. In our previous study of 26 Taiwanese patients with a median age of 76.5, only one case was HIV-positive, while the others were either negative or presumed negative based on the clinical setting [10].…”

“…In addition to the classic HHV8-related PEL, there are reports of sporadic cases and small series of HHV8-unrelated effusion lymphomas. Supplementary Table S1 lists all the HHV8-negative PEL cases in the English literature from 1996 to 2021 that we reviewed [4,7,[10][11][12][13][14]16,17,38,. There are a total of 167 cases, with the majority (92.2%, n = 154) being large cells with a B-cell phenotype, with rare cases of plasmablastic (3.0%; n = 5), T-cell (1.0%; n = 2), and indeterminate phenotype (3.6%; n = 6).…”

“…Although HHV8-negative PELs are cytomorphologically similar to classic HHV8-related PEL, such cases are clinically distinct from those with classic PEL (Table 2). These patients are generally HIV-negative and up to half of the cases might have underlying medical conditions, such as by liver cirrhosis and heart failure, leading to fluid overload state [10,12,13,38,45,89]. Wu et al reviewed 55 cases of HHV8-negative PEL and found liver cirrhosis and heart disease in 10 (18%) and 9 (16%) cases, respectively [12].…”

“…Morphologically, plasmablastic cells are large in size with eccentrically located nuclei, prominent nucleoli, and basophilic/amphophilic cytoplasm [91]. Most HHV8-unrelated type II PEL demonstrate cytological characteristics ranging from immunoblasts to highly pleomorphic cells, which resemble those commonly found in classic PEL, yet these effusion lymphomas are usually of B-cell phenotype (Figure 2) [10][11][12]38]. In rare cases, the phenotype in terms of B-cell vs. plasmablastic is indeterminate (Figure 3).…”

Primary HHV-8 (-) Effusion-Based Non-Germinal Center B Cell Diffuse Large B Cell Lymphoma Successfully Treated with Standard Anthracycline-Based Chemoimmunotherapy

“…Other reports of PEBL have also interestingly documented complete remission following thoracentesis alone as well as spontaneous regression without any treatment whatsoever, with remissions lasting up to multiple years in certain cases. 7,9,19,21,27 This response of PEBL to drainage alone is in clear discrepancy with PEL as Alexanian et al's review notably reported that 70% of PEBL patients experienced partial or complete remission following thoracentesis alone as compared to only 18% of PEL patients. 5 Although thoracentesis alone is a promising treatment option, we propose that thoracentesis alongside R-CHOP should be used in eligible patients since the data supporting thoracentesis alone is quite limited at this time.…”