Nocardiosis diagnosed on bronchoalveolar lavage: Role of cytopathology

Nocardia are gram-positive, filamentous bacteria that have the potential to cause serious disease, particularly in immunocompromised patients. Nocardia may cause a complex clinical picture, with radiologic features that can mimic other infectious organisms or malignancy. The organisms are not easily identified on cytologic examination given their weak staining with routine preparations and because they may be obscured by the associated inflammatory exudate. However, recognition of subtle features and a high index of suspicion in the appropriate clinical setting can lead to the appropriate triaging of material for ancillary stains and confirmatory microbiology tests. We herein present three cases of nocardiosis diagnosed on bronchoalveolar lavage in order to discuss the clinical presentation and cytomorphologic features with emphasis on the role of cytopathologists in facilitating timely diagnosis and helping direct appropriate management.