Alveolar proteinosis

• Rare disorder in which lipoproteinaceous material accumulates in alveoli due to altered surfactant homeostasis
• Male preponderance
• Associated with smoking

Chest radiographic findings are often inconclusive. HRCT demponstrates a combination of ground-glass and interlobular opacities, often in a crazy-paving pattern with geographic involvement.

Differential for Crazy Paving - ground glass opacities and septal thickening

• Alveolar proteinosis
• Bronchoalveolar carcinoma
• Pneumocystis pneumonia (PCP)
• Pulmonary hemorrhage
• Inhalation of silica dust
• Lipoid pneumonia
• Drug toxicity