A case of atypical cells in the urinary sediment of a patient with methotrexate-associated lymphoproliferative disorders

Abstract

Although methotrexate (MTX) is a highly effective drug in rheumatoid arthritis (RA) patients, it also has various side effects. Lymphoproliferative disorders (LPDs) are one of them, and they have a unique feature of disappearing when MTX is discontinued. We encountered a case in which LPD developed in an RA patient who was using MTX, and atypical cells that were considered to be derived from hematopoietic tumors were found in the patient’s urine. There have been very few reports of MTX-LPD onset in the kidney, and it was important to confirm the patient’s medical information and background.