Human Herpes virus 8-negative primary effusion lymphoma with BCL6 rearrangement in a patient with idiopathic CD4 positive T-lymphocytopenia

Abstract

Primary effusion lymphoma (PEL) was initially designated as a body-cavity-based lymphoma and recognized as a distinct clinical entity without a contiguous tumor mass. PEL was first reported in patients with acquired immunodeficiency syndrome (AIDS) and the distinctive feature of PEL originally reported as a B-cell neoplasm characterized by infection of the tumor cells by human herpes virus 8 (HHV-8).1 However, there have recently been several reports of PEL in patients without human immunodeficiency virus (HIV) or HHV8 infection.2–4

A 78-year-old male was admitted to our hospital for dyspnea. A computed tomographic scan of the chest and abdomen showed pericardial and pleural effusion, but there was no evidence of tumor masses, lymph node enlargement, or hepatosplenomegaly. Cytologic examinations of the effusion revealed large-sized lymphoid cells with immunophenotypes positive for CD19, CD20, CD22, IgM, IgD. Results of PCR analyses using the cells were positive for EBV, but negative for HHV8. BCL-6 gene rearrangement was detected by Southern blotting and FISH. The counts for leukocytes, lymphocytes and CD4 lymphocytes in his peripheral blood were 4000, 840 and 126 × 10/L, respectively, without evidence of immunodeficiency. The patient was diagnosed as PEL associated with idiopathic CD4 T-lymphocytopenia (ICL).

The patient was treated with rituximab and THP-COP regimen, and achieved remission. At the time of this report he had been free from PEL for more than 30 months after the chemotherapy although the low level of T lymphocytes continues persisted.

This is the first case of PEL developed in a patient with ICL. In contrast to PEL associated with HIV infection, the lymphoma cells were negative for HHV8 infection but positive for BCL6 rearrangement and Ig expression, and successfully treated with chemotherapy.