CSP: chronic inflammation and progressive fibrosis of the pulmonary alveolar walls with steady progressive dyspnea; finally, resulting in death from lack of oxygen or right heart failure.,MSH: A common interstitial lung disease of unknown etiology, usually occurring between 50-70 years of age. Clinically, it is characterized by an insidious onset of breathlessness with exertion and a nonproductive cough, leading to progressive DYSPNEA. Pathological features show scant interstitial inflammation, patchy collagen fibrosis, prominent fibroblast proliferation foci, and microscopic honeycomb change.,NCI: A disease in which the alveoli (tiny air sacs at the end of the bronchioles in the lungs) are overgrown with fibrous tissue. The cause of the disease is unknown and it gets worse over time. Symptoms include difficult, painful breathing and shortness of breath.,NCI: Chronic and progressive fibrosis of the lung parenchyma of unknown cause.