2016 Volume 55 Issue 4 Pages 250-255
Background : Methotrexate is a frequently used medication for rheumatoid arthritis, and several types of lymphomas have been reported as adverse effects of this treatment. We report a rare case of MTX-related lymphoproliferative disorders occurring on the synovial membrane.
Case : The patient was a 62-year-old woman who had been diagnosed as having rheumatoid arthritis 9 years earlier and received treatment with MTX for the previous 8 years. She presented to us with an 8-month history of progressively worsening swelling and sharp pain of the left knee joint. Cytological examination of a synovial fluid specimen from the left knee joint led to the suspicion of methotrexate-associated lymphoproliferative disorders, and the excised synovial membrane was histologically examined.
Conclusion : Cases of MTX-LPD limited to the synovial membrane are very rare, and in the present case, cytological diagnosis was made by immunostaining of cell block samples. Data of 9 cases of MTX-LPD other than the present case filed in the Niigata Prefectural Rheumatism Center were also reviewed.
