A 53-year-old female nonsmoker is being evaluated with symptoms of progressive shoness of breath. She has a past history of trauma to the right side of the chest. There is no history of asthma, sputum production, or recent chest pain. CXR is shown in,The likely diagnosis is

There is a large, well-demarcated, calcified pleural-based opacity abutting the lateral chest occupying two-thirds of the left hemithorax. It has a rounded, intensely calcified inferior and medial border and thus suggests a pleural origin. The shadow is most consistent with a large, old organized hemothorax. The calcified and organized pleuralbased opacity is consistent with an old hemothorax secondary to previous trauma. The pulmonary functions in this case would show restrictive limitation due to fibrosis of the pleural space and decreased lung compliance.