Mechanisms of lung tissue restructuration. A structural analysis of experimental and human materials.

Lung tissue restructuration is one of the most important components of chronic pneumopathies. Comparison of experimental and human data regarding the dynamic evolution of variously induced chronic lung processes pointed out as main mechanisms the bronchial and bronchiolar obstructions, the viral and fungal pneumonitic processes, the parenchymatous suppurative processes, the granulomatous organization of cellular reactions, the interlobular cell accumulations, the hypersensitivity reactions, and the lesions of small vessels. Mostly acting in association, these dynamic conditions determine the fibroplastic transformation of lesions, the exclusion of unventilated areas, the destruction of respiratory surfaces, the clear predominance of connective tissue structures, sometimes with ossifications; some microcavities persist within restructuring areas, sometimes delimited by alveolar or bronchiolar epithelia. The honeycomb lung is one of the evolutive possibilities of this restructuration of damaged tissues during chronic lung diseases.