[Two fatal cases of methotrexate-induced interstitial pneumonitis].

: We report two cases of methotrexate-induced pneumonitis. Both patients died despite steroid pulse therapy. Postmortem lung tissue revealed diffuse alveolar damage, and focal lung fibrosis. Physicians should be aware of the possibility of MTX-induced interstitial pneumonitis in diagnosing RA patients with MTX when diffuse pulmonary infiltration is present.