Abstract
Methotrexate (MTX)-related lymphoproliferative disease (LPD) is one of the most prominent late complications associated with MTX treatment. Although MTX-related LPD exhibits a relatively high incidence of extranodal disease, the incidence of disease in a urinary bladder is very low. The present study reports the case of a patient with MTX-related LPD involving a urinary bladder mass. A 75-year-old female patient, who had been receiving MTX for ~15 years, was referred to the hospital due to fever and hematuria. A computed tomography scan revealed the thickening of the urinary bladder wall, hydronephrosis and lymph node swelling. The histopathological findings of the urinary bladder mass resulted in a diagnosis of MTX-related LPD. Although MTX withdrawal did not have any effect, the subsequent chemotherapy resulted in complete remission. Although MTX-related LPD in the bladder is rare, it is pertinent to consider MTX-related LPD when hematuria is observed during MTX therapy.