Desquamative interstitial pneumonia

Desquamative interstitial pneumonia
Diagnosis in short
LM	abundant brown pigmented airspace macrophages (smoker's macrophages), architecture preserved ("linear fibrosis")
LM DDx	amiodarone toxicity, fibrotic NSIP, RBILD
Site	lung - see diffuse lung diseases
Associated Dx	smoking
Prevalence	uncommon
Treatment	stop smoking

Desquamative interstitial pneumonia, abbreviated DIP, is a diffuse lung disease that is strongly associated with smoking.

General

• Thought to be advanced RBILD.
• Strong association with smoking.
  • Treatment: stop smoking.

Microscopic

Features:

• Abundant brown pigmented airspace macrophages - smoker's macrophages - key feature.
• Architecture preserved; "linear fibrosis".

Notes:

• Some fields of view may be indistinguishable from RBILD.

DDx:

• Amiodarone toxicity.
• Fibrotic NSIP.
• RBILD.

Images

• DIP (ucsf.edu).

Stains

• Macrophages PAS +ve.

See also

• Diffuse lung diseases.