부산대학교 도서관

Background. Methotrexate-associated lymphoproliferative disorders (MTX-LPDs) are rare entities in patients treated with MTX, and only a few cases reports have described the presence of complex endobronchial or pulmonary lesions. In particular, intratracheal lesions are rarely observed by bronchoscopy and their definitive diagnosis is obtained by a transbronchial biopsy (TBB) under direct visualization. Case. An 83-years-old woman had been started on MTX+prednisolone for overlap syndrome of rheumatoid arthritis and systemic scleroderma in 2016 by her previous doctor. In June 2020, chest computed tomography showed a mass shadow in the middle lobe of the right lung, and she was referred to our hospital for suspected lung cancer. We obtained a definite diagnosis of diffuse large B-cell lymphoma (DLBCL) by a TBB under direct visualization. The diagnosis of MTX-LPDs were made based on the additional immunostaining results and clinical history. Conclusion. When intratracheal or pulmonary lesions are found in patients treated with MTX, there are many differential diagnoses. We should keep in mind of MTX-LPDs, and if possible, bronchoscopic observation and a biopsy should be performed for the examination.