6 Patterns > Cellular Infiltrates

Cellular Infiltrates Pattern

You have selected the cellular infiltrates pattern! 

Patients with cellular infiltrates pattern biopsies typically present subacutely with cough and SOB over weeks to months.  The imaging studies show bilateral infiltrates and ground-glass opacities.  Your biopsy should look blue from low-power due to the presence of inflammatory cells in the interstitium.  If you still think you have a cellular infiltrates pattern biopsy, click the link below.  

If you're still unsure if you're dealing with a cellular infiltrates pattern, explore other histologic examples below.

Expanded Intersitium

Interstitium is expanded by an inflammatory cell infiltrate. The alveolar walls have a “rigid” appearance.  

Mixed Inflammation

In some cases the interstitium will be expanded by cells other than lymphocytes, like PMNs in this case of DAH.

Variable Fibrosis

There may be a component of diffuse fibrosis in the background of cellular infiltrates.

Organizing Acute Lung Injury 

Organizing ALI is a pitfall in the cellular infiltrates pattern as the edema and influx of inflammatory cells in the proliferative phase and mimic cellular infiltrates.  If you are considering ALI, investigate further here.

Classic Cellular Infiltrates

Lymphocytes and plasma cells expanding the interstitium.

If your biopsy has the above features, you are in the appropriate category of fibrosis.  But your job is not complete by recognizing fibrosis.

Sample Signout

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.