Mediastinal Tumors are benign or cancerous growths that form in the area of the chest that separates the lungs. This area, called the mediastinum, is surrounded by the breastbone in front, the spine in back, and the lungs on each side. The mediastinum contains the heart, aorta, esophagus, thymus and trachea. These rare tumors demand careful evaluation and specialized expertise for an accurate diagnosis.