<unk> s in a case of vaping-associated pulmonary injury. Left: Papanicolaou stain; right: Oil Red O stain.<unk> s, also known as pulmonary foam cells, are cells found in bronchoalveolar lavage (BAL) specimens that consist of<unk> s containing deposits of<unk> s (fats). The<unk>  content of the<unk> s can be demonstrated using a<unk>  targeting stain like Oil Red O or Nile red. Increased levels of<unk> s are associated with various respiratory conditions, including chronic smoking, gastroesophageal reflux,<unk>  pneumonia, fat embolism, pulmonary<unk>  proteinosis and pulmonary aspiration.<unk> s have been reported in cases of vaping-associated pulmonary injury. The<unk><unk><unk>  index (LLMI) can be calculated by counting 100<unk> s in a BAL specimen treated with a<unk>  stain and scoring each<unk>  from 0 to 4 based on the amount of<unk> s present in the cell. A LLMI score greater than 100 is considered positive for pulmonary aspiration. However, the test is limited by poor reproducibility and low specificity for pulmonary aspiration, as<unk><unk><unk> s occur in many respiratory conditions.
Lipid-laden alveolar macrophage
Multifocal micronodular pneumocyte hyperplasia
Non-specific interstitial pneumonia
Lymphocytic interstitial pneumonia
Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia
Epithelial basement membrane dystrophy
Intraepithelial lymphocyte
Plasma cell granuloma