<prompt> The histologic entity that has the worst prognosis in interstitial lung disease is:Non-specific interstitial pneumoniaDesquamative interstitial pneumoniaAcute interstitial pneumoniaUsual interstitial pneumonia  <response>: Ans: c Acute interstitial pneumoniaRef: Rosai and Ackermans Surgical Pathology 9th ed Pg. 377, Harrison 18th ed chp 261Acute Interstitial Pneumonia Hamman-Rich Syndrome A fulminant form of lung injury characterized by idiopathic ARDS and organizing diffuse alveolar damage by lung biopsy. The onset is usually abrupt following a prodromal illness. CXR - Diffuse, bilateral, air-space opacification. HRCT - bilateral, patchy, symmetric areas of ground-glass attenuation areas of air-space consolidation. A predominantly subpleural distribution may be seen. The mortality rate is high 60, most patients die within 6 months. Treatment is supportive, glucocorticoid therapy role not clear. 