[B-cell lymphoma possessing t(14;18)(q32;q21)in a patient with rheumatoid arthritis receiving methotrexate treatment].

ABSTRACT

There is evidence of a slight increase in malignant lymphoma among rheumatoid arthritis(RA)patients receiving methotrexate( MTX). Increased rates of lymphoma have been attributed to reactivation of the Epstein-Barr virus(EBV). A 72-yearold woman was admitted to our hospital for generalized lymph adenopathy. She suffered from RA and has been treated with MTX for 7 years; the total amount of MTX received was around 2, 700 mg. The cervical lymph node revealed a diffuse proliferation of large atypical lymphocytes. An immunophenotype revealed CD10+, CD19+, CD20+, and k+. The chromosome analysis showed a complex abnormality containing t(14;18)(q32;q21). The tumor cells were positive for EBV sequences by in situ hybridization(ISH). A rituximab containing regimen was effective, but a systemic relapse occurred 4 years later. The biopsied sample was diagnosed as diffuse large B-cell lymphoma. FISH analysis revealed positive for t(14;18)(q32;q21), however, EBV was negative using ISH. In general, the concurrence of t(14;18)(q32;q21)and EBV in the B-cell lymphoma is rare. In addition, the negative change in EBV in the relapsed lymphoma cells revealed a quite rare phenomenon.