The mediastinum is the thoracic space between the visceral pleura of the lungs. The boundaries of the mediastinum are the visceral pleura, thoracic inlet (spine, first ribs, and manubrium), diaphragm, sternum, and anterior spinal ligaments. The contents of the mediastinum include the heart, great vessels, trachea, esophagus, thymus gland, lymphatic tissue, and nerves. Tumors may arise from any of these structures. The mediastinum is commonly divided into the anterior, middle, and posterior compartments. Occasionally, radiographic or anatomic texts may refer to a superior compartment, which adds little to clinical management.
Anterior mediastinal contents include:
Middle mediastinal contents include:
Pericardium, heart, ascending and descending aorta, great vessels
Trachea and carina
Posterior mediastinal contents include:
Proximal intercostal vessels
Thoracic spinal ganglion
Sympathetic nerve chain
Instructor in Surgery
Division of Thoracic Surgery
Massachusetts General Hospital
Harvard Medical School
AM declares that he has no competing interests.
Dr Ashok Muniappan would like to gratefully acknowledge Dr John Kucharczuk, Dr Mario Gasparri, and Dr Nicholas Choong, the previous contributors to this monograph. JK, MG, and NC declare that they have no competing interests.
Department of Internal Medicine
University of Rochester
MB declares that he has no competing interests.
University Associate Professor
Albert Einstein College of Medicine
Director Aortic Surgery
Montefiore Medical Center
AD declares that he has no competing interests.
Assistant Professor of Surgery
Section of Cardiac and Thoracic Surgery
The University of Chicago
SAA declares that he has no competing interests.
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