honeycomb lung
Honeycombing is a CT imaging descriptor referring to clustered cystic air spaces (between 3-10 mm in diameter, but occasionally as large as 2.5 cm) that are usually subpleural, peripheral and basal in distribution. They can be subdivided into:
microcystic honeycombing
macrocystic honeycombing
The walls of the cysts are well-defined and often thick (1-3 mm) .
They represent an irreversible finding commonly seen in diffuse pulmonary fibrosis (usual interstitial pneumonia (UIP)).