EBV-positive MTX-diffuse large B cell lymphoma in a rheumatoid arthritis patient.

Methotrexate (MTX)-associated lymphoproliferative disorders have received much attention from rheumatologists, and early diagnosis is very important for reducing mortality. There are several reports of radiologic findings in patients with pulmonary malignant lymphoma, mainly consisting of masses, nodules, and lymphadenopathy. Computed tomography has rarely detected necrosis in the masses. In this article, we report a case of MTX-associated Epstein-Barr virus-positive diffuse large B-cell lymphoma characterized by a very large lung mass with prominent areas of central necrosis. The disease regressed after withdrawal of MTX.