Methotrexate-Induced Lymphoproliferative Disorder Complicating Into Spontaneous Tumor Lysis Syndrome and Disseminated Intravascular Coagulation.

Lymphoproliferative disorder (LPD) is a severe adverse outcome of methotrexate (MTX) administration in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). The immunosuppression caused is attributed to pathogenesis. Hence, discontinuation is the treatment. Reports on spontaneous tumor lysis with cessation of MTX are rare. We report a case of a female in her 50s with methotrexate-associated lymphoproliferative disease (MTX-LPD) following treatment for rheumatoid arthritis. Methotrexate was discontinued immediately. She presented two months later with severe disseminated intravascular coagulation (DIC) and spontaneous tumor lysis syndrome (STLS). Although tumor lysis syndrome responded well to rasburicase therapy, DIC was a challenge. MTX-LPD has various complications and highly variable presentation. RA/SLE patients receiving MTX should be regularly monitored, and MTX should be immediately stopped in suspicion of MTX-LPD. Although many patients respond to MTX cessation, some patients head to remission and relapse. At the same time, some worsen with complications such as DIC and tumor lysis syndrome, as described above. This case reiterates the need for regular monitoring following MTX therapy cessation for early identification and treatment of these complications to improve prognosis.