GO WITH THE FLOW: A RARE CASE OF PRIMARY EFFUSION LYMPHOMA

Abstract

TOPIC: Lung Pathology TYPE: Fellow Case Reports INTRODUCTION: Primary effusion lymphoma (PEL) is a very rare and extremely aggressive form of non-Hodgkin's lymphoma which originates in body cavities without forming a true mass. It predominately affects individuals with HIV/AIDS, but can occur in other patient populations, such as those with chronic HCV and solid organ transplant recipients. PEL accounts for less than 1% of all HIV related lymphoma cases. CASE PRESENTATION: 56 year old male with AIDS (CD4 count 128 not on treatment), HFrEF 45%, HCV, drug abuse, who initially presented with recurrent multifocal pneumonia associated with a right sided parapneumonic effusion. A thoracentesis was performed with removal of exudative pleural fluid. Given his history of AIDS, the decision was made to send pleural fluid for cytology and flow cytometry. The results showed CD38+ cells representing 80% of cells (as well as CD45 and CD138), consistent with primary effusion lymphoma. PEL was then confirmed by the presence of HHV8 and EBV, as well as elevated serum beta 2 macroglobulin levels. Cytology and flow cytology from BAL, EBUS, and bone marrow were negative for malignancy. During his hospitalization, he was started on antiretroviral treatment and chemotherapy, and as a palliative measure, talc pleuredesis was performed which helped abate the rapid recurrence of his malignant pleural effusion. DISCUSSION: Primary effusion lymphoma (PEL) is a very rare form of large B cell lymphoma that is characterized by the presence of a malignant effusion affecting a single cavity (in this case right pleural effusion) without a discernable tumor mass, and carries a poor prognosis. PEL overwhelmingly affects immunocompromised patients, usually HIV/AIDS but also can affect solid transplant recipients. Usually these neoplastic cells are associated with HHV8 and EBV as was seen in this case. Diagnosis is made by flow cytometry of effusion, which is usually a pleural effusion but can also present as a pericardial effusion, ascites, or joint effusions. The reason for development of malignant effusions as presenting sign of PEL is not fully understood, and due to the rarity of the disease, clinical data is lacking regarding management. Treatment currently entails antiretroviral therapy, chemotherapy (typically a CHOP like regimen), and/or radiation. The lack of CD20 expression renders anti-CD20 monoclonal antibodies ineffective as a treatment modality which likely contributes to the 1 year survival rate < 40% in those who undergo treatment. CONCLUSIONS: Due to the rarity of primary effusion lymphoma and lack of a mass to guide suspicion, diagnosis can be challenging. However, in an immunocompromised patients presenting with effusions, PEL should be on the differential, and fluid analysis with flow cytometry should be obtained. However, prognosis remains poor due to the aggressive nature of the disease, delay in diagnosis, and lack of effective treatment options. REFERENCE #1: https://doi.org/10.1182/blood-2018-03-791426 REFERENCE #2: Blood. 1997;90(3):1186. DISCLOSURES: No relevant relationships by Ahmad Alkhasawneh, source=Web Response No relevant relationships by Milca Isaac, source=Web Response No relevant relationships by Mariam Louis, source=Web Response No relevant relationships by Monique Oye, source=Web Response No relevant relationships by Peter Staiano, source=Web Response