Lymphoma with regression after methotrexate withdrawal in a patient with rheumatoid arthritis. Role for the Epstein-Barr virus.

We report a new case of large T-cell lymphoma in a rheumatoid arthritis patient under low-dose methotrexate (cumulative dose: 750 mg). Serologic tests for the Epstein-Barr virus were positive, and the viral RNA was demonstrated in the lymphoma cells. As in a few other cases reported in the literature, the clinical and laboratory test abnormalities resolved promptly after methotrexate withdrawal without anticancer therapy. The patient was still in complete remission at last follow-up four years later.