[Alveolar type II cells in centrilobular emphysema lesions of human lung--an ultrastructural study]

The lungs studied were surgically resected, mainly for lung cancer. All lungs had centrilobular emphysema. Emphysematous and non-emphysematous areas were identified by dissecting light microscopy. In emphysematous lesions, transmission electron microscopic observation revealed that (1) the shape of type II cells was associated with the changes of alveoli, such as type II cells were flattened in flattened alveolar wall; (2) the cells were cuboidal in the alveolar corner; (3) the number of close contacts between type II cells and interstitial cells was significantly decreased; (4) osmiophilic lamellated bodies in type II cells were normal in number and shape, and that type II cell hyperplasia was observed in the overlapping alveolar walls. These findings suggest that both injury and repair may occur in the alveolar epithelium of emphysematous lesions, and tissue repair may be impaired.