A Case of Methotrexate-induced Other Iatrogenic Immunodeficiency-associated Lymphoproliferative Disorder with Diffuse Ground-glass Opacities Diagnosed Using a Cryobiopsy.

Methotrexate (MTX)-induced iatrogenic immunodeficiency-associated lymphoproliferative disorder (OIIA-LPD) usually presents as multiple pulmonary nodules or masses. However, we herein present a rare case demonstrating diffuse ground-glass opacities (GGOs). The patient was a 77-year-old woman with a history of rheumatoid arthritis and advanced gastric cancer. Because of the markedly elevated serum lactate dehydrogenase levels and diffuse GGOs on chest computed tomography, intravascular lymphoma was considered. A transbronchial lung cryobiopsy (TBLC) was performed to obtain tissue specimens for a histopathological evaluation, leading to a diffuse large B-cell lymphoma diagnosis after multidisciplinary discussions. To the best of our knowledge, this is the first report of MTX-induced OIIA-LPD diagnosed by TBLC.