A case of desquamative interstitial pneumonia with unidentified etiology

Desquamative Interstitial Pneumonia (DIP) is a rare form of interstitial lung disease, most commonly associated with cigarette smoking. However, in certain cases, environmental, occupational, or immunological factors may play a predominant role. Histopathologically, DIP is characterized by a diffuse and uniform inflammatory process involving the alveolar lumen and interstitium, with the presence of numerous large, mononuclear macrophages in the alveolar spaces and septa. It typically exhibits minimal or moderate septal thickening due to limited collagen deposition and contains few inflammatory cells. Compared to other interstitial pneumonias, DIP generally has a more favorable prognosis. Smoking cessation and corticosteroid therapy have been reported to yield excellent outcomes. Herein, we present a rare case of DIP in a young adult patient with no history of smoking or identifiable environmental exposure, who demonstrated resistance to standard therapy.