INTRODUCTION:Primary effusion lymphoma (PEL) is an uncommon non-Hodgkin’s lymphoma (NHL) of B-cell origin that proliferates exclusively in serous body cavities such as the pleura, pericardium, and peritoneum. The vast majority of PEL’s occur patients infected with human immunodeficiency virus (HIV), and are associated with human herpesvirus 8 (HHV8). PEL has rarely been diagnosed in non-HIV patients. We describe an unusual case of a primary B-cell lymphoma of the pleural fluid not associated with HHV8 that occurred in an HIV-negative elderly man after recent chemotherapy for prostate cancer.
CASE PRESENTATION:An 80 year-old man was admitted to the hospital with a 4-week history of dyspnea on exertion and orthopnea. He had a history of metastatic prostate cancer treated with imatinib mesylate and docetaxel until two months prior to admission. He denied chest pain, fever, chills, cough or weight loss. On physical exam his vital signs were normal. On lung auscultation he had decreased basilar breath sounds with dullness to percussion, greater on the right. Abdominal exam was normal without organomegaly, and there were no palpable lymph nodes. A computerized tomography (CT) of the chest revealed bilateral pleural effusions, right greater than left, with no infiltrates, masses or lymphadenopathy. A right-sided thoracentesis was performed, which revealed clear yellow fluid with a total protein (TP) of 5.1 g/dL, lactate dehydrogenase (LDH) level of 41,920 IU/L, and glucose less than 30 mg/dl. Simultaneous serum TP and LDH levels were 8.9 g/dL and 1302 IU/L, respectively. Cholesterol and triglycerides of the pleural fluid were within normal limits, and gram stain and cultures were negative. Cytologic analysis revealed abundant abnormal cells consistent with large B-cell lymphoma, with a Burkitt’s-type morphology. The cells were Epstein-Barr virus (EBV)-positive by in-situ hybridization and negative for HHV8 by immunohistochemistry. A subsequent left-sided thoracentesis revealed similar results. CT scans of the abdomen and pelvis revealed no evidence of lymphadenopathy or organomegaly, and bone marrow biopsy with flow cytometry showed no evidence of malignancy. Complete blood count with differential, liver function tests, and serum chemistries were within normal limits and HIV-antibodies and hepatitis panel were negative. After the diagnosis of PEL was established, cyclophosphamide, vincristine and dexamethasone therapy were initiated and a Denver catheter was inserted for palliation. The patient expired eight months after diagnosis.
DISCUSSIONS:PEL, also known as body cavity lymphoma, is usually defined as a B-cell lymphoma occurring in a body cavity without direct extension from a solid tissue component. The definition of PEL according to the World Health Organization Classification of Tumors includes an association with HHV8, and EBV positivity has been reported in approximately 70% of cases (1). HHV8 negative PEL, however, is a rare entity that has yet to be clearly defined. Previous case reports usually described elderly patients, frequently of Japanese origin. Our literature review found only three reported cases of HHV8-negative, HIV- negative, EBV-positive malignant effusion lymphomas, and, to our knowledge, this is the first reported case of a malignant effusion lymphoma in the setting of previous chemotherapy. Further investigation is required to determine which factors predispose this heterogenous group of HIV-negative, HHV8 negative patients to developing PEL.
CONCLUSION:HHV8-negative, EBV-positive malignant effusion lymphoma in non-HIV patients is a rare but emerging entity that necessitates further clinicopathological study.
DISCLOSURE:Nisha Rathi, No Financial Disclosure Information; No Product/Research Disclosure Information