Home   Chapter Home   Jobs   Conferences   Fellowships   Books



Other interstitial pneumonitis / fibrosis

Desquamative interstitial pneumonitis (DIP)

Reviewers: Elliot Weisenberg, M.D. (see Reviewers page)
Revised: 24 September 2011, last major update September 2011
Copyright: (c) 2003-2011, PathologyOutlines.com, Inc.


● Usually adults with insidious onset of shortness of breath, progressing to respiratory insufficiency; also cough, cyanosis and clubbing
● Cause unknown
● Mean survival of 12 years, mortality 28%
● 90% are current or past cigarette smokers; male:female = 2:1
● Patients who stop smoking +/- steroid therapy have good prognosis
● Associated with collagen vascular disease, positive ANA (similar to UIP)
Xray: bilateral, lower lobe, ground glass infiltrates


● Steroids (respond better than UIP)

Micro description

● Diffuse collections of intraalveolar macrophages containing lipid and PAS+ granules (originally thought to be desquamated pneumocytes)
● Type II pneumocyte hyperplasia, acute and chronic inflammatory cells
● May be focal interstitial fibrosis
● No necrosis, no hyaline membranes and no fibrin

Virtual slides


Positive stains

● PAS after diastase, iron

EM description

● Type II pneumocytes contain lamellar bodies (surfactant)
● May be phagocytosed by macrophages

Differential diagnosis

● DIP reaction to Langerhans cell histiocytosis
● Extrinsic allergic alveolitis
● Asbestosis
● Respiratory bronchiolitis

End of Lung-nontumor > Other interstitial pneumonitis / fibrosis > Desquamative interstitial pneumonitis (DIP)

This information is intended for physicians and related personnel, who understand that medical information is often imperfect, and must be interpreted in the context of a patient's clinical data using reasonable medical judgment. This website should not be used as a substitute for the advice of a licensed physician.

All information on this website is protected by copyright of PathologyOutlines.com, Inc. Information from third parties may also be protected by copyright. Please contact us at [email protected] with any questions (click here for other contact information).