- Accumulation of periodic acid Schiff positive lipoproteinaceous material in alveoli
- Due to abnormal surfactant clearance from lungs
- Fault in GM-CSF signaling
- Primary – idiopathic due to anti GM-CSF antibodies
- Secondary – dust inhalation, infections, myelodysplasia, lymphoma, myeloid leukemia
- 20-50 years
- M>F
- More in children
- Definitive diagnosis: bronchoalveolar lavage, biopsy
Imaging
- Chest Xray
- Nonspecific
- Both lungs affected
- Airspace opacification predominantly in central lung – bat’s-wing appearance
- CT
- Crazy paving pattern – geographical areas of ground-glassing with thick inter and intralobular septa.
- Differentials for crazy paving pattern: adenocarcinoma, exogenous lipoid pneumonia, pulmonary edema
Read more
Frazier, Aletta Ann, et al. “Pulmonary alveolar proteinosis.” Radiographics 28.3 (2008): 883-899.