Cytologic diagnosis of respiratory syncytial virus infection in a bronchoalveolar lavage specimen from a bone marrow transplant recipient.

Cytologic examination of a bronchoalveolar lavage specimen from a 6-year-old bone marrow transplant recipient revealed pulmonary infiltrates and occasional cells containing discrete pink cytoplasmic inclusions on a May-Grunwald-Giemsa stain. Direct immunofluorescence stains of cytospins prepared from the same specimen were positive for respiratory syncytial virus (RSV). Electron microscopy revealed occasional epithelial cells with cytoplasmic inclusions composed of filamentous virions. The patient died 6 months after the specimen was taken. An autopsy showed ongoing bronchiolitis with diffuse alveolar damage. Occasional bronchiolar epithelial cells contained discrete eosinophilic cytoplasmic inclusions, which on ultrastructural examination proved to be compatible with RSV. Examination of bronchoalveolar lavage fluid from bone marrow transplant recipients should include a search for cytopathic changes compatible with RSV infection. Electron microscopy can be helpful in confirming this diagnosis.