A case of completely resolved pneumatocoeles in desquamative interstitial pneumonia.

Desquamative interstitial pneumonia (DIP), also known as alveolar macrophage pneumonia (AMP), represents a subset of idiopathic interstitial pneumonia that responds better to steroids and has a more favourable prognosis than usual interstitial pneumonia. Recently, we encountered a case of DIP with the formation of multiple pulmonary cysts during corticosteroid maintenance treatment. After the introduction of cyclophosphamide, the cysts gradually disappeared. This complete resolution is believed to have resulted from the clearance of check-valve-like bronchiolar obstructions that may be another interesting terminal airway pathology in DIP.