Pulmonary involvement in infectious mononucleosis: histopathologic features and detection of Epstein-Barr virus-related DNA sequences.

Symptomatic pulmonary parenchymal involvement is rare in infectious mononucleosis, and few pathologic descriptions of this lesion exist. We describe an unusual patient who presented with adenopathy and rapidly progressive interstitial lung disease. An open lung biopsy showed a predominantly interstitial infiltrate of mononuclear cells distributed along lymphatic routes. A patchy alveolar exudate was also seen. Biopsy of a paratracheal lymph node showed paracortical hyperplasia typical of infectious mononucleosis. The diagnosis was suspected only after thoracotomy and was established by appropriate serological studies for Epstein-Barr virus. Epstein-Barr virus genomic sequences were also detected within routinely processed lung and lymph node tissues using polymerase chain reaction technology. Infectious mononucleosis should be considered in the differential diagnosis of certain lymphoid lung lesions.