Acid-fast-positive Legionella pneumophila: A possible pitfall in the cytologic diagnosis of mycobacterial infection in pulmonary specimens

• Published in: Diagnostic cytopathology Vol. 22; no. 1; pp. 45 - 48
• Main Authors: Bentz, Joel S., Carroll, Karen, Ward, John H., Elstad, Mark, Marshall, C. Jay
• Format: Journal Article
• Language: English
• Published: New York John Wiley & Sons, Inc 01.01.2000; Wiley-Liss
• Subjects: acid-fast stain; Bacterial diseases; Bacterial diseases of the respiratory system; Biological and medical sciences; bronchoalveolar lavage; Bronchoalveolar Lavage Fluid - microbiology; Cytodiagnosis; Diagnosis, Differential; Human bacterial diseases; Humans; Infectious diseases; Legionella; Legionella pneumophila - isolation & purification; Legionnaires' Disease - complications; Legionnaires' Disease - diagnosis; Male; Medical sciences; Middle Aged; mycobacteria; Mycobacterium Infections - diagnosis; Pneumonia, Bacterial - diagnosis; Prostatic Neoplasms - complications; pulmonary; Staining and Labeling; Human; Lung disease; Legionellaceae; Respiratory disease; Staining; Legionella pneumophila; Male; Legionellosis; Mycobacterial infection; Differential diagnostic; Infection; Case study; Pathology; Immunosuppression; Bronchoalveolar lavage; Bacteriosis; Bacteria; Adult; Cytopathology
• ISSN: 8755-1039; 1097-0339
• DOI: 10.1002/(SICI)1097-0339(200001)22:1<45::AID-DC12>3.0.CO;2-Y

The acid‐fast stain is commonly used in the rapid cytologic assessment of bronchoalveolar lavage (BAL) fluid to detect pulmonary mycobacterial infections, particularly in immunocompromised patients. The identification of acid‐fast, rod‐shaped organisms may be taken as presumptive evidence of such an infection, in the appropriate clinical setting. However, this determination is made less specific by the occasional acid‐fast positivity of microorganisms other than mycobacteria. We report on the occurrence of a fatal pneumonia caused by acid‐fast positive Legionella pneumophila detected by BAL. This is a potential pitfall in the rapid diagnosis of pulmonary mycobacterial infections. Diagn. Cytopathol. 2000;22:45–48. © 2000 Wiley‐Liss, Inc.