[New highlight of acute interstitial pneumonia]

Acute interstitial pneumonia (AIP) is a rare lung disease recently included into the classification of idiopathic interstitial pneumonias as a distinctive disease, even though the clinical description was made more than 80 years ago, and the characteristic pathological findings were reported two decades ago. The diagnostic features have been established based on case series with limited number of patients enrolled with to different inclusion criteria,. This is an important bias when defining the clinical outcome and prognosis of the disease. The hospitalized mortality rate has been estimated higher than 50%, relapse and progressive fibrosis being most reported outcome. Recent studies describe a better prognosis in relation to HR-CT findings and to an early intervention, according to our own experience.