A 62-year-old man is a smoker with a 10-year history of cough productive of copious mucopurulent sputum. Over the past 6 months, he has developed progressive dyspnea. Physical examination shows bilateral pedal edema and a soft but enlarged liver. A chest radiograph shows bilateral pleural effusions and a prominent right heart border. Arterial blood gas values are PO2, 60 mm Hg; PCO2, 52 mm Hg; pH, 7.30; and HCO3-, 29 mEq/L. He is intubated and placed on a ventilator, and he requires increasing amounts of oxygen. Which of the following microscopic findings is most likely to be present in the affected lungs?

Chronic bronchitis can be complicated by pulmonary hypertension and cor pulmonale. There are few characteristic microscopic features of chronic bronchitis, so it is mainly defined clinically by the presence of a persistent cough with sputum production for at least 3 months in at least 2 consecutive years. Chronic bronchitis does not lead to diffuse pulmonary fibrosis. Granulomatous disease is more typical of sarcoidosis or mycobacterial infection. Lymphangitic metastases may fill lymphatic spaces and produce a reticulonodular pattern on a chest radiograph, but patients tend not to live long with such advanced cancer. Increased eosinophils are characteristic of bronchial asthma, which is an episodic disease unlikely to cause cor pulmonale.