Abstract
Methotrexate-associated lymphoproliferative disorder (MTX-LPD) is well known as a lymphoma caused by long-term and low dose administration of methotrexate (MTX) for the treatment of rheumatoid arthritis. In the World Health Organization (WHO) classification, MTX-LPD is categorized into immunodeficiency-related lymphoproliferative disorders. Although tissue types are varied in this disease, most of them are permitted provided Hodgkin's lymphoma and diffuse large B-cell lymphoma. In this report, we highlighted two cases of methotrexate-associated lymphoproliferative disorders in the gingiva. The cases received MTX oral medication for their rheumatoid arthritis treatment during a period of 13–15 years. Physical examination revealed the ulceration of the gingiva with alveolar bone exposure and pathological diagnosis of diffuse large B-cell lymphoma was made. Following MTX interruption, symptoms were completely remitted.
