A Case of Methotrexate-associated Lymphomatoid Granulomatosis

Background. Methotrexate, a folate metabolism antagonist, is a first-line drug for rheumatoid arthritis, which can induce lymphoproliferative disorders. Case. A 73-year-old female had been treated with methotrexate for rheumatoid arthritis for 14 months. A chest CT scan showed multiple pulmonary nodules bilaterally. A transbronchial biopsy, CT-guided percutaneous lung biopsy and ultrasonography-guided liver biopsy did not lead to a diagnosis; therefore, partial resection of the lung was performed under video-assisted thoracoscopic surgery. The histopathology revealed lymphomatoid granulomatosis (grade 2), and the abnormal shadows were immediately reduced by methotrexate withdrawal. Conclusion. We herein reported a rare case of methotrexate-associated lymphomatoid granulomatosis.