Abstract
Methotrexate（MTX）-associated lymphoproliferative disorder（MTX-LPD）is one of the side effects of MTX, and their reports is the oral cavity are rare. We report a case in which MTX-LPD with a wide range of osteonecrosis of jaw bone（ONJ）. A 70-year-old woman was referred on our clinic because of bone exposure after teeth extraction on the right side of the maxillary first molar region. She was rheumatoid arthritis（RA）patient and had received MTX and predonisolone for 15 years. Histopathologically, biopsy specimens were diagnosed EBV- positive diffuse large B cell lymphoma（DLBCL）. We requested discontinuation of MTX and their gingival lesions were decreased and symptoms disappeared, but their bone exposed lesions were increased. Therefore, she resived surgical treatments. There have been no signs of recurrence for 12 months.
