Hyaline membrane disease is also known as respiratory distress syndrome of the newborn and as adult respiratory distress syndrome (ARDS). The condition is characterized histologically by the presence of a hyaline membrane which lines the alveolar walls. This membrane consists of a fibrin exudate and the necrotic debris of cells. Other characteristics are the breakdown of endothelial and type1 cells and the proliferation of type 2 pneumocytes.
In this slide there is a hyaline membrane (glassy pink membrane) lining the 4 visible alveoli . Note that the other alveoli have been obliterated by RBCs and other cells.