Auntminnie: Crazy Paving Pattern in PAP (Pulmonary alveolar proteinosis)

Fig. Axial CT of the chest shows diffuse bilateral ground-glass opacities superimposed by interlobular septal thickening (arrowheads) and intralobular lines (blue arrows). Note a left chest tube used to treat left pneumothorax, which brought this patient to the hospital.

This case is a radiologist auntminnie!

What is "Crazy-Paving" Pattern?
- Ground-glass opacity superimposed with interlobular septal thickening and intralobular lines
- Can be scattered or diffuse
- Can be caused by alveolar filling process, interstitial process, or a combination

What Can Cause "Crazy-Paving" Pattern?
- CLASSIC: Pulmonary alveolar proteinosis
- COMMON: Pneumocystis jirovecii pneumonia (PCP), pulmonary edema (ARDS), pulmonary hemorrhage
- NOT COMMON: Bronchioloalveolar carcinoma, alveolar sarcoidosis, nonspecific interstitial pneumonitis (NSIP), Cryptogenic organizing pneumonia (COP), lipoid pneumonia
- Our case is a patient with biopsy proven pulmonary alveolar proteinosis.

Reference:
1. Rossi SE, et al. "Crazy-Paving" Pattern at Thin-Section CT of the Lungs: Radiologic-Pathologic Overview. Radiographics 2003;23:1509.
2. Johkoh T, et al. Crazy-paving Appearance at Thin-Section CT: Spectrum of Disease and Pathologic Findings. Radiology 1999;211:155.

This case was provided by our partner, RadiologyinThai (http://www.radiologinthai.com)