Diffuse pneumonia and acute respiratory failure due to infectious mononucleosis in a middle-aged adult.

This report describes a 48-yr-old patient who developed bilateral hilar adenopathy, diffuse pulmonary infiltrates, and respiratory failure in association with infectious mononucleosis. Lung and paratracheal lymph node biopsies suggested the diagnosis, and an acute Epstein-Barr virus infection was confirmed serologically. Pulmonary involvement in infectious mononucleosis is reviewed, and atypical features, which may lead to diagnostic difficulty, particularly in the older adult, are discussed.