label: Desquamative interstitial pneumonitis
label_lc: desquamative interstitial pneumonitis
description: Diffuse filling of the distal airspaces of the lungs, the alveoli, with macrophages. Desquamative interstitial pneumonitis (DIP) is characterized additionally by thickened alveolar septa and by a sparse inflammatory infiltrate that often includes plasma cells and occasional eosinophils. The alveoli are lined by plump cuboidal pneumocytes. Lymphoid aggregates may be present.