anomalies of contents
- red cells (alveolar hemorrhage)
- nucleate cells
- alveolar granulocytes
- alveolar lymphocytes
- alveolar macrophages
- alveolar proteinosis
- amniotic debris and keratin squames (amniotic aspiration)
- alveolar hyaline membranes
- alveolar meconium (meconial aspiration)
alveolar fibrosis
- organizing pneumonia