Macrophages with abundant cytoplasm containing dusty brown pigment are seen in

Desquamative interstitial pneumonia is characterized by large collections of macrophages in the airspaces in a current or former smoker. The macrophages were originally thought to be desquamated pneumocytes, thus the misnomer "desquamative interstitial pneumonia."The most striking finding is the accumulation of a large number of macrophages with abundant cytoplasm containing dusty brown pigment (smokers' macrophages) in the airspaces.Ref: Robbins and Cotran Pathologic basis of DIsease; 9th edition; Chapter 15; The lung; Change 682