A 60-year-old man, a heavy smoker, presents for advice to stop smoking. On physical examination, he is thin and has a ruddy complexion. He has a productive cough and a barrel-shaped chest. He sits leaning forward with his lips pursed to facilitate his breathing. A diagnosis of emphysema is made. Which of the following is the most likely histologic finding in the lungs?: (A) Bronchial smooth muscle hyperophy with proliferation of eosinophils, (B) Diffuse alveolar damage with leakage of protein-rich fluid into alveolar spaces, (C) Dilation of air spaces with destruction of alveolar walls, (D) Hyperplasia of bronchial mucus-secreting submucosal glands
Answer is C. Emphysema is an example of COPD. Due to the destruction of alveolar walls, a lack of elastic recoil causes air to become trapped in alveoli, and, thus, airflow obstruction occurs on expiration. In COPD, FEV1 is decreased, whereas FVC is normal or increased; therefore, patients with COPD have a decreased FEV1 :FVC ratio.