Rare diseases · Sign or symptom
Crazy paving pattern
HP:0025391
What it means
The so-called crazy paving pattern appears as thickened interlobular septa and intralobular lines superimposed on a background of ground-glass opacity, resembling irregularly shaped paving stones. The crazy-paving pattern is often sharply demarcated from more normal lung and may have a geographic outline. It was originally reported in patients with alveolar proteinosis and is also encountered in other diffuse lung diseases that affect both the interstitial and airspace compartments, such as lipoid pneumonia.
See Figure 20 of Hansell DM, et al., Fleischner Society: glossary of terms for thoracic imaging. Radiology. 2008;246:697-722.
Rare diseases that can present with this2
The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.
Part of the broader category
Also called: Crazy paving pattern on pulmonary HRCT · Crazy-paving pattern
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Start free with EleplanThis page uses the Human Phenotype Ontology (2026-06-23) — Human Phenotype Ontology Consortium, hpo.jax.org. Disease associations from Orphanet (INSERM), CC BY 4.0. Content is educational and is not medical advice.