A case of intraoral methotrexate-assosiated lymphoproliferative disorder

Methotrexate （MTX） has been used not only for cancer and leukemia therapy, but also for the treatment of rheumatoid arthritis （RA）. However, some reports caution that MTX might induce MTX-associated limphoproliferative disorders （MTX-LPD）. We report a case of MTX-LPD associated with a gingival ulcer, which led to the diagnosis. A 66-year-old woman was referred to our hospital because of a chronic gingival nlcer of the maxilla. She had been receiving predonisolone （PSL） and MTX for over 12 years to treat RA. She had noticed an upper gingival ulcer 2 months before presentation, which gradually increased in size. Computed tomography showed bone resorption in the anterior region of the maxilla. Reported pathological examination revealed diffuse large B-cell lymphoma and immunohistochemistry supported the diagnosis of MTX-LPD. After stopping MTX,removing the necrotic bone, and antibacterial chemotherapy, the ulcer spontaneously resolved.