On HRCT chest, the 'crazy paving' pattern (ground-glass opacity with superimposed interlobular septal thickening) is classically associated with:
- A Hypersensitivity pneumonitis
- B Lymphoid interstitial pneumonia
- C Pulmonary alveolar proteinosis ✓
- D Pulmonary Langerhans cell histiocytosis
Correct answer: C. Pulmonary alveolar proteinosis
Explanation
Crazy paving on HRCT (geographic GGO with superimposed interlobular and intralobular septal thickening forming a crazy-paving appearance) is the classic pattern of pulmonary alveolar proteinosis, where lipoproteinaceous material fills alveoli. The pattern can also be seen in lipoid pneumonia and some infections. Hypersensitivity pneumonitis shows centrilobular nodules and mosaic attenuation. Langerhans cell histiocytosis shows centrilobular nodules and bizarre-shaped cysts in upper-lobe distribution.
Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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