[Human herpesvirus 8-negative primary effusion lymphoma-like lymphoma with t(8;14)(q24;q32)]

Primary effusion lymphoma (PEL) is a large B-cell lymphoma proliferating only in the body cavity effusion. It often occurs in advanced AIDS patients and is associated with human herpesvirus 8 (HHV-8). On the other hand, HHV-8 negative effusion lymphoma, which is different from PEL in many ways, has also been reported and is referred to as HHV8-unrelated PEL-like lymphoma. This lymphoma is very rare and its clinical characteristics have not yet been fully clarified. We therefore report an HIV seronegative elderly patient with HHV8-unrelated PEL-like lymphoma. An 89-year-old woman was admitted to our hospital due to general fatigue and dyspnea. The patient presented with left pleural effusion in the absence of lymphadenopathy and tumor masses. The pathological examination of the pleural effusion showed proliferation of atypical large lymphoid cells, which were positive for CD19, CD20, CD10, CD38, CD7, BCL2 and BCL6 but negative for CD5, CD30, MUM1, surface immunoglobulin, HHV-8 and EBV. Cytogenetic analysis showed a complex karyotype including t(8;14)(q24;q32). The pleural effusion decreased in response to monotherapy with oral low-dose etoposide, but recurrence was detected 7 months later. Rituximab was transiently effective for the recurrent pleural effusion, but the patient died of lymphoma exacerbation 13 months after the diagnosis.