Honeycombing or "honeycomb lung" is the radiological appearance seen with widespread fibrosis and is defined by the presence of small

cyst A cyst is a closed sac, having a distinct envelope and division compared with the nearby tissue. Hence, it is a cluster of cells that have grouped together to form a sac (like the manner in which water molecules group together to form a bubble) ...

ic spaces with irregularly thickened walls composed of

fibrous tissue Fiber or fibre (from la, fibra, links=no) is a natural or artificial substance that is significantly longer than it is wide. Fibers are often used in the manufacture of other materials. The strongest engineering materials often incorporate ...

. Dilated and thickened terminal and respiratory bronchioles produce cystic airspaces, giving honeycomb appearance on chest x-ray. Honeycomb cysts often predominate in the peripheral and pleural/subpleural lung regions regardless of their cause. Subpleural honeycomb cysts typically occur in several contiguous layers. This finding can allow honeycombing to be distinguished from paraseptal emphysema in which subpleural cysts usually occur in a single layer.

References

{{Reflist Lung disorders