Pulmonary cryptococcosis mimicking methotrexate pneumonitis.

An 81-year-old man being treated with weekly low dose methotrexate (MTX) for psoriasis was admitted with a 2-month history of cough, shortness of breath and 7% eosinophilia in the peripheral blood. Chest roentgenogram revealed bilateral alveolar and interstitial infiltrates. Although the clinical presentation suggested MTX pneumonitis, a transbronchial lung biopsy established a diagnosis of pulmonary cryptococcosis. Pulmonary cryptococcosis should be included in the list of infectious processes that can mimic MTX pneumonitis.