Current Concepts in Primary Effusion Lymphoma and Other Effusion-Based Lymphomas

Primary effusion lymphoma (PEL) is a human herpes virus 8 (HHV8)-positive large B-cell neoplasm that presents as an effusion with no detectable tumor in individuals with human immunodeficiency virus infection or other immune deficiencies. PEL is an aggressive neoplasm with a poor prognosis. PEL cells show diverse morphologies, ranging from immunoblastic or plasmablastic to anaplastic. The immunophenotype of PEL is distinct, but its lineage can be misdiagnosed if not assessed thoroughly. PEL cells usually express CD45, lack B- and T-cell-associated antigens, and characteristically express lymphocyte activation antigens and plasma cell-associated antigens. Diagnosis of PEL often requires the demonstration of a B-cell genotype. HHV8 must be detected in cells to diagnose PEL. In most cases, PEL cells also harbor the Epstein-Barr virus (EBV) genome. Similar conditions associated with HHV8 but not effusion-based are called "extracavitary PELs." PELs should be differentiated from HHV8-negative, EBV-positive, body cavity-based lymphomas in patients with long-standing chronic inflammation; the latter can occur in tuberculous pleuritis, artificial pneumothorax, chronic liver disease and various other conditions. Despite their morphological similarity, these various lymphomas require different therapeutic strategies and have different prognostic implications. Correct diagnosis is essential to manage and predict the outcome of patients with PEL and related disorders.

A Case of Human Herpes Virus-8 Unrelated Primary Effusion Lymphoma-Like Lymphoma Presented as Pleural Effusion / 결핵및호흡기질환

Primary effusion lymphoma (PEL) is a rare type of lymphoma that arises in the body cavity without detectable masses. It is associated with human herpes virus-8 (HHV-8), Epstein-Barr virus (EBV), and human immunodeficiency virus (HIV). Recently, PEL unrelated to viral infection has been reported and it has been termed HHV-8 unrelated primary effusion lymphoma-like lymphoma (HHV-8 unrelated PEL-like lymphoma). Here, we report a case of HHV-8 unrelated PEL-like lymphoma in an 80-year-old woman. Chest X-ray and computed tomography revealed left-sided pleural effusion. Pleural effusion analysis and mediastinoscopic biopsy showed atypical cells that had originated from the B cells. The cells were positive for CD20 and bcl-2, but negative for CD3, CD5, CD21, CD30, CD138, epithelial membrane antigen, and HHV-8. Serological tests for HIV and EBV were negative. Considering the patient's age, further treatments were not performed. She has shown good prognosis without chemotherapy for more than 18 months.