Methotrexate-associated lymphoproliferative disorders (MTX-LPD) comprise lymphoid proliferations in subjects with autoimmune disease, especially rheumatoid arthritis (RA) treated with methotrexate (MTX).
These disorders are recognized as a distinct disease entity in the 2001 World Health Organization classification. We herein report on our experience with 8 patients suffering from RA as an underlying disease who developed MTX-LPD of the head and neck region during the 4-year period from May 2008 to January 2012. Among these cases, one typical patient in whom discontinuation of MTX resulted in remission is described in detail. MTX 8 mg weekly was administered to a 50-year-old woman with RA. She suffered from a sore throat for two months and right tonsil swelling that eventually developed into an ulcer.
Based on the histopathological findings from a tonsil biopsy, she was diagnosed as having diffuse large B-cell lymphoma. Clinically, she was diagnosed as having MTX-LPD, and MTX was discontinued. The oropharyngeal tumor gradually shrank, and 1 month after MTX withdrawal, the lesion had disappeared. Her clinical course continues to be good with no sign of recurrence.
MTX-LPD is expected to increase as MTX is used increasingly to treat RA. We should therefore take MTX-LPD in consideration when examining subjects treated with MTX.