Pathology and pathophysiology of chronic obstructive pulmonary disease

A variety of pathological changes have been observed in the central airways, peripheral airways and lung parenchyma of patients with chronic obstructive pulmonary disease (COPD). The characteristic changes in the central airways include inflammatory cellular infiltration into the airway wall and mucous gland enlargement. In the peripheral airways, various morphological changes are observed, including mucous plugging, epithelial abnormalities, inflammatory cellular infiltrates, fibrosis and distortion; these changes lead to airway narrowing. In the lung parenchyma, emphysema defined as alveolar destruction and airspace enlargement is present. Although the major sites of airflow limitation in patients with COPD are most likely the peripheral airways, lesions in both the peripheral airways and the lung parenchyma contribute to chronic airflow limitations.