Gram‐ghost bacilli

A 76‐year‐old man presented with a 3‐day history of a productive cough and right chest pain on inspiration. The Gram stain of the sputum showed unstained bacilli and polynuclear leukocytes, suggesting a diagnosis of pulmonary acid‐fast bacillus infection. Mycobacteria can be identified by Gram staining and are reported to be Gram‐neutral or Gram‐ghost, and recognition of Gram‐ghost bacilli in the initial specimen may assist in distinguishing mycobacterial infection from community‐acquired pneumonia.[Image: see text]