2019 Volume 25 Issue 2 Pages 44-50
Methotrexate-associated lymphoproliferative disorder （MTX-LPD）, which may develop in the oral cavity, is known to be associated with the administration of methotrexate. We herein report a case of MTX-LPD that developed in the buccal mucosa. The patient was a 64-year-old woman who had undergone long-term methotrexate treatment for rheumatoid arthritis and who complained of ulcer formation in the bilateral buccal mucosa. The pathological diagnosis was diffuse large B-cell lymphoma with Epstein-Barr virus-positive cells. The lesions improved following the withdrawal of methotrexate. The development of MTX-LPD in the buccal mucosa is very rare.