Mediastinum, thymus, cervical and thoracic trachea, and lung

The mediastinum exists by definition as an area defined by arbitrary anatomic boundaries within which many intrathoracic organs reside. The mediastinum's existence by definition has led not only to confusion but also to controversy regarding its anatomic subdivisions. This in turn has led to confusion in the radiologic, medical, and surgical literature reporting frequency of different tumors within the mediastinum. The organs and tumors within the mediastinum are many. This section defines the mediastinum and its compartments, the contents within, surgical procedures for diagnosis, and representative surgical techniques within each compartment.