Honeycombing (lungs)

Honeycombing refers to the computed tomographic (CT) manifestation of diffuse pulmonary fibrosis (usual interstitial pneumonia). The Fleischner Society definition is clustered cystic air spaces (between 3-10 mm in diameter but occasionally as large as 2.5 cm) which are usually subpleural and basal in distribution. The walls of the cysts are well-defined and often thick (1-3 mm) ⁴. 

Honeycombing is an irreversible finding in interstitial lung disease and associated with a poor prognosis.

Pathology

Honeycombing consists of enlarged airspaces with thick fibrotic wall lined by bronchiolar epithelium and often filled with mucin and inflammatory cells ⁶.

Differential diagnosis

• air-space consolidation in the presence of pulmonary emphysema can mimic this appearance.
• in some situations, paraseptal emphysema and paracicatrical emphysema can also mimic honeycombing ³

Etymology

The term “honeycomb lung” is thought to have originated in the 19^th century in Germany and is thought to have  first appeared in 1949 in a study by N Oswald and T Parkinson ⁵.

See also

• microcystic honeycombing
• macrocystic honeycombing