咽頭痛を主訴に初診したメトトレキサート関連リンパ増殖性疾患の1例

A case of methotrexate-associated lymphoproliferative disorders

Ⅰ　はじめに

　メトトレキサート（methotrexate：MTX）は慢性関節リウマチ（rheumatoid arthritis：RA）の治療や抗腫瘍薬として広く使用されている薬剤である。1991年にMTX投与中のRA患者にリンパ腫が発生することが報告^1）されて以来，同様の報告が散見され，近年MTX関連リンパ増殖性疾患（methotrexate-associated lymphoproliferative disorders：MTX-LPD）として注目されている。

　今回われわれは急性扁桃炎様の所見を認め発症したMTX-LPDの1例を経験したので報告する。

　A 70-year-old female suffered from rheumatoid arthritis and was treated with methotrexate for seven years. She complained of sore throat and antibiotic-resistant redness of her left tonsil,which was eventually developed into an ulcer. Biopsy of the left tonsil was performed. Histopathologically,the sample of tissue was composed of large atypical cells showing positive staining for CD20,CD30 and Epstein-Barr virus-encoded small RNA 1 and negative staining for CD15 with a rich inflammatory background. She was diagnosed of methotrexate-associated lymphoproliferative disorders（“Hodgkin-like lesions”）. Methotrexate was discontinued and the systemic chemotherapy was established. After the initial treatment,no evidence of recurrence has been observed for 14 months.