Alveolar microlithiasis

  • Deposition of tiny stones mainly made of calcium phosphate in air spaces
  • Mutations in SLC34A2 gene. This gene codes for sodium dependent phosphate transporter in type II alveolar cells
  • Causes phosphate accumulation
  • 30-50 years age
  • Asymptomatic at presentation
  • Chest Xray
    • Widespread discrete high density opacities (resembling sand grains)
    • When profusely involving lungs, similar to a white out appearance
    • Obscuration of heart borders and diaphragm
    • Black sub pleural lung due to small cysts or paraseptal emphysema 
    • Thickening or beading of fissures
    • Apical blebs
    • Kerley B lines rarely
  • CT
    • Widespread ground-glass opacification
    • Micro nodular pattern
    • Predominantly lower zones and posteriorly
    • Thickening of fissures and interlobular septa
    • Crazy paving pattern
Read more

Ufuk, Furkan. “Pulmonary Alveolar Microlithiasis.” Radiology 298.3 (2021): 567-567.

Delic, Joseph A., Carl R. Fuhrman, and Humberto E. Trejo Bittar. “Pulmonary alveolar microlithiasis: AIRP best cases in radiologic-pathologic correlation.” Radiographics 36.5 (2016): 1334-1338.