Grade 3 lymphomatoid granulomatosis in a patient receiving methotrexate therapy for rheumatoid arthritis.

Lymphomatoid granulomatosis (LyG) is a rare, B-cell derived, lymphoproliferative disorder that often presents as pulmonary nodular lesions with a histopathology of lymphatic invasion of the vascular wall. The development of LyG may be associated with reactivation of the Epstein-Barr virus under an immunosuppressive state. We herein report a case of Grade 3 LyG that developed during methotrexate therapy for rheumatoid arthritis and regressed following the withdrawal of the drug.