“Empyema thoracis, from the Greek, is defined as ‘‘pus in the chest.’’ The most common precursor of empyema is bacterial pneumonia and subsequent parapneumonic effusion. Other causes of empyema include bronchogenic carcinoma, esophageal rupture, blunt or penetrating chest trauma, mediastinitis with pleural extension, infected congenital cysts of the airway and esophagus, extension from sources below the diaphragm, cervical and
thoracic spine infections, as well as postsurgical etiologies.”