Pulmonary alveolar proteinosis
 Discussion of Pulmonary alveolar proteinosis
- Pulmonary alveolar proteinosis (PAP) manifests as filling of the alveoli by a proteinaceous material that is positive at periodic acid–Schiff staining and rich in lipid, in association with an inflammatory response in the adjacent interstitium.
- PAP is most common in adults between 20 and 50 years of age.
- Dyspnea and nonproductive cough are the most common associated symptoms.
- The diagnosis/treatment is with bronchoalveolar lavage.
- Patients with PAP are susceptibility to pulmonary infections. Infectious agents include and opportunistic pathogens (especially nocardia) and common respiratory pathogens.
 Imaging Findings for Pulmonary alveolar proteinosis
 Plain film
- Classic radiographic finding is bilateral, symmetric alveolar consolidation or ground-glass opacity, particularly in a perihilar or hilar distribution resembling pulmonary edema.
- CT typically shows diffuse ground-glass attenuation with superimposed crazy-paving pattern (intra- and interlobular septal thickening, often in polygonal shapes representing the secondary pulmonary lobule).
Patient #1: Proven PAP but not quite the classic crazy-paving pattern
 See Also
 External Links
 References for Pulmonary alveolar proteinosis
- Santiago E. Rossi, Jeremy J. Erasmus, Mariano Volpacchio, Tomas Franquet, Teresa Castiglioni, and H. Page McAdams. "Crazy-Paving" Pattern at Thin-Section CT of the Lungs: Radiologic-Pathologic Overview. RadioGraphics 2003 23: 1509-1519.
- ACR Case in Point 6/17/05