A Rare Case of Other Iatrogenic Immunodeficiency-Associated Lymphoproliferative Disorders With Multiple Oral Mucosal Lesions During Methotrexate Therapy.

As of the most recent WHO classification of immunodeficiency diseases, lymphoproliferative disorders that occur during treatment with immunosuppressive drugs are classified as "other iatrogenic immunodeficiency-associated lymphoproliferative disorders (OIIA-LPDs)" other than post-transplant lymphoproliferative disorders. Most patients with OIIA-LPD have rheumatoid arthritis as the underlying disease. Research indicates that approximately half of people diagnosed with OIIA-LPD see a remission of their lesion after stopping treatment with methotrexate (MTX), a drug used in rheumatoid arthritis treatment. Hereby, we present the case of an 81-year-old woman with rheumatoid arthritis who developed OIIA-LPD at the bilateral lingual margins. The patient had been receiving MTX for the preceding 10 years. After determining that OIIA-LPD was MTX-related, the patient underwent MTX withdrawal and was treated conservatively. The lesion resolved one month after MTX withdrawal. This case report confirms immunosuppressive drug withdrawal as a potentially effective treatment for multiple OIIA-LPDs of the oral mucosa.