6 Patterns > Fibrosis Pattern > Additional Features

Fibrosis Sub-Patterns

There are 7 sub-patterns in the setting of fibrosis.

Click the image most similar to your case.  It may be OK to see more than one pattern. 

w/ Variable involvement

  • UIP/IPF

  • Connective Tissue Disease

  • Chronic Hypersensitivity Pneumonitis

  • Pneumoconiosis

  • Others (rare)

w/ Diffuse alveolar wall fibrosis

  • Idiopathic NSIP

  • Connective Tissue Disease

  • Drug toxicity

  • Pneumoconiosis

  • Smoking related interstitial fibrosis

  • Chronic Hypersensitivity Pneumonitis

  • Healed acute lung injury

  • Immunodeficiency disease

w/ Granulomas

  • Chronic Hypersensitivity Pneumonitis

  • Sarcoidosis/Berylliosis

  • Certain chronic infections

  • Chronic Aspiration

w/ Honeycomb Only

  • If diffuse disease on CT, UIP and others

  • If focal disease on CT, middle lobe, post infectious, aspiration, etc.

w/ Airway-centered distribution

  • Chronic Hypersensitivity Pneumonitis

  • Chronic aspiration

  • Adverse drug reaction

  • Connective Tissue Disease

  • Smoking/inhalational

  • Chronic/recurrent infection

  • Idiopathic disease

w/ Pleuritis and/or lymphoid hyperplasia 

  • Connective Tissue Disease

w/ acute lung injury

  • Acute exacerbation of underlying ILD

Sample Signout of the Fibrotic Pattern

If no additional specific histologic features are identified, consider the following approach to signing the case out:

Fibrosing Interstitial pneumonia (see comment).

Comment:  The biopsy shows advanced fibrosis with architectural distortion.  No additional specific histologic features to indicate an etiology are identified.  There is a broad differential diagnosis including UIP, advanced NSIP, chronic HP, and CTD-associated ILD among others.  The diagnosis of ILD requires a multidisciplinary approach.  Correlation with imaging studies and clinical history is suggested.