Table 1 Histopathological criteria for UIP/IPF[1]
From: The current position of surgical lung biopsy in the diagnosis of idiopathic pulmonary fibrosis
1. UIP pattern (All four criteria) | 2. Probable UIP pattern | 3. Possible UIP pattern (All three criteria) | 4. Not UIP pattern (Any of the six criteria) |
|---|---|---|---|
1. Marked fibrosis/architectural distortion, ± honeycombing in a predominantly subpleural/paraseptal distribution | 1. Marked fibrosis/architectural distortion, ± honeycombing | 1. Patch or diffuse involvement of lung parenchyma by fibrosis, with or without interstitial inflammation | 1. Hyaline membranes |
2. Organizing pneumonia | |||
3. Granulomas | |||
2. Presence of patchy involvement of lung parenchyma by fibrosis | 2. Absence of either patchy involvement or fibroblast foci, but not both | 2. Absence of other criteria for UIP (see UIP pattern column) | 4. Marked interstitial inflammatory cell infiltrate distant from honeycombing |
3. Presence of fibroblast foci | 3. Absence of features against a diagnosis of UIP suggesting an alternate diagnosis (see fourth column) | 3. Absence of features against a diagnosis of UIP suggesting an alternate diagnosis(see fourth column) | 5. Predominant airway centered changes |
4. Absence of features against a diagnosis of UIP suggesting an alternate diagnosis (see fourth column) | OR | Â | 6. Other features suggestive of an alternate diagnosis |
| Â | 4. Honeycomb changes only | Â | Â |