Usual interstitial pneumonia

What it means

Temporal and spatial heterogeneity in lungs based on presence of fibrosis and honeycombing.

Usual interstitial pneumonia (UIP) is usually identified by a honeycombing pattern in a CT scan; in contrast, diffuse interstitial pneumonia (DIP) is not associated with the honeycombing pattern of fibrotic tissue. DIP tends to stabilize or improve after treatment, UIP often continues to progress (irregular lines or honeycombing). Honeycombing, clustered cysts with well-defined walls involving the subpleural lung, is the key finding for making a definite diagnosis of UIP pattern. UIP is associated with autoimmune diseases such as rheumatoid arthritis (and rheumatoid arthritis-interstitial lung disease, or RA-ILD).

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