INTRODUCTION: Primary effusion lymphoma (PEL) represents an unusual entity of B-cell neoplasm with a predilection for body cavities such as the peritoneal, pleural, and pericardial spaces. It is the least common AIDS-related lymphoma comprising 4% or less of lymphomas. Although most cases occur in immunocompromised or human immunodeficiency virus (HIV)-infected patients in addition to infection with human herpesvirus-8 (HHV-8) or Epstein-Barr virus (EBV), PEL occurs in HIV-negative patients. We describe a case of a woman with HIV-negative PEL treated with CHOP and Rituximab.
CASE PRESENTATION: A 50-year old woman with metabolic syndrome and chronic kidney disease stage 3 was admitted to the hospital with a 2-week history of cough, chills, epigastric pain, and exertional dyspnea. She had a pericardial effusion 18 months earlier with flow cytometry negative for lymphoma. Physical exam revealed diminished breath sounds over the left lung with decreased fremitus. Chest radiograph showed a massive left-sided pleural effusion which layered freely on decubitus films. Computed tomography of the chest revealed a large left-sided pleural effusion with compressive atelectasis with celiac lymphadenopathy but no mediastinal adenopathy or masses. Thoracentesis revealed a serosanguinous, lymphocyte predominant pleural effusion with a high lactate dehydrogenase and high adenosine deaminase. Cytological analysis demonstrated a monotonous population of large sized atypical lymphocytes with round to multilobulated nuclei. Immunohistochemistry showed neoplastic cells positive for CD20 and PAX-5, negative for CD10, negative for HHV-8, and a Ki-67 proliferation index of 85%. Flow cytometry revealed a monoclonal B-cell population that is CD19, CD20, CD38 and CD45 positive consistent with diffuse large B-cell lymphoma. The patient started chemotherapy with CHOP and Rituximab.
DISCUSSIONS: We describe a case of a woman with a history of pericardial effusion now with a massive left-sided pleural effusion with celiac lymphadenopathy but no mediastinal adenopathy. The differential diagnosis for patients with a lymphocyte predominant pleural effusion with a high lactate dehydrogenase and adenosine deaminase include malignancy, tuberculosis, empyema, rheumatoid pleuritis, Q fever, and brucellosis. The patient's clinical findings, cytomorphological features, and absence of mass lesion supports the diagnosis of PEL. Laboratory studies excluded the other diagnoses. Primary effusion lymphomas express a common gene profile that is distinct from that of other AIDS-related non-Hodgkin's lymphomas or lymphomas in the immunocompetent population. The tumor cells correspond to a stage of B-cell development intermediate between that of immunoblasts and plasma cells. The survival of PEL cells depends on the unregulated production of nuclear factor-kappa B (NF-kB). NF-kB are inducible transcriptional factors that activate gene transcription driving lymphocyte proliferation and survival. Inhibition of NF-kB has been shown to induce apoptosis in PEL cells. Multiagent chemotherapy regimens used for other types of high-grade lymphomas tend to be less effective for PEL. Chemotherapy with a modified CHOP regimen administered every 28 days is given with the expectation that the patient will have a rapid decrease in the tumor, as determined by the size of the effusion, within the first two cycles of chemotherapy. If such a response does not occur, it is unlikely that further cycles of this regimen will be effective. If such a response does occur, then four to six cycles are given depending upon when a complete clinical response is attained. In our case, the patient's neoplasm expresses the CD20 antigen suggesting a potential benefit with the monoclonal chimeric antibody Rituximab.
CONCLUSION: In patient's with a history of pericardial effusion who present with a large lymphocyte predominant pleural effusions with a very high lactate dehydrogenase and adenosine deaminase consider the diagnosis of PEL.
DISCLOSURE: Gilbert Seda, No Financial Disclosure Information; No Product/Research Disclosure Information