A 59-year-old man has had increasing dyspnea on exertion for the past year. His dyspnea is worse in the upright position and diminishes when he is recumbent. On physical examination, he has clubbing of the fingers. Exercise induces a decrease in his PO2 that improves when he stops and lies down. Which of the following liver abnormalities is he most likely to have?

Hepatopulmonary syndrome (portopulmonary hypertension) is described. The cause is obscure, but the result is pulmonary arterial vasoconstriction and ventilation-perfusion (V/Q) mismatches that lead to hypoxemia. The remaining choices are conditions that do not cause portal hypertension. Chronic inflammation and steatosis may be seen with cirrhosis, but by themselves do not account for portopulmonary hypertension. Metastases tend to be focal, leaving residual functioning hepatic parenchyma. Biliary obstruction leads to jaundice.