Characteristic histopathological finding in SHOCK LUNG-

Ref: Textbook of pathology ( Harshmohan)6th edition, page no.46 Morphological Feature of Shock Lung Grossly, the lungs are normal in size. They are characteristically stiff, congested, heavy and airless so that they sink in water. Microscopically, the impoant features are as follows . 1.There is presence of collapsed alveoli (atelectasis) alternating with dilated alveoli. 2.Necrosis of alveolar epithelial cells and formation of characteristic eosinophilic hyaline membranes lining the respiratory bronchioles, alveolar ducts and the proximal alveoli. The membrane is largely composed of fibrin admixed with cell debris derived from necrotic alveolar cells. 3.Interstitial and intra-alveolar oedema, congestion and intra-alveolar haemorrhages. 4.Changes of bronchopneumonia may supervene. 5.With time, compensatory proliferation of pneumocytes into alveolar lumen may be seen as tufts of alveolar epithelium. 6.In organising stage, there is interstitial fibrosis obliterating alveolar spaces.