Alveolar proteinosis

  • 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
  • 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.

Rossi, Santiago E., et al. ““Crazy-paving” pattern at thin-section CT of the lungs: radiologic-pathologic overview.” Radiographics 23.6 (2003): 1509-1519.