Methotrexate-related lymphomatoid granulomatosis : a case report of spontaneous regression of large tumours in multiple organs after cessation of methotrexate therapy in rheumatoid arthritis

We describe a 54‐year‐old female patient with rheumatoid arthritis (RA) and Sjogren's syndrome (SS) who presented with right chest pain and a large mass visible in the upper right field of a chest X‐ray. Computed tomography (CT) showed multiple tumours in both lungs, the liver, and the spleen. The right lung tumour was 8 cm in diameter with a cavity. Biopsy of the lung and liver revealed lymphomatoid granulomatosis (LG) and diffuse large B‐cell lymphoma (DLBCL). These lesions spontaneously regressed after withdrawal of methotrexate without any therapy for the lymphoma. This is the first report of self‐limiting LG in a patient, complicated with methotrexate‐treated RA.