The mediastinum is the area in the chest between the lungs, that contains the heart, the aorta, part of the windpipe (the trachea), and the esophagus -- essentially all of the organs in the chest except the lungs. It is also home to many lymph nodes.
You can visualize this area by seeing the diagphram as the bottom, the breast bone (the sternum) as the front, the blood vessels that enter and exit the heart as the top, and the backbone (the vertebral column) as the back side.
The mediastinum is divided into 3 main regions:
- Anterior - Is present only on the left side and contains some small arteries as well as lymph nodes.
- Middle - Is the largest portion, and contains the heart, blood vessels including those that travel from the lungs to the heart, and lymph nodes.
- Posterior - This part contains the esophagus, many blood vessels and nerves, and lymph nodes.
With cancers such as lung cancer and lymphomas, doctors often evaluate the mediastinum to see if any cancer has spread to this region. One procedure that allows surgeons to visualize this area is called a mediastinoscopy. If a cancer has spread to nodes in the mediastinum it is often treated differently than a cancer which has not spread to this region