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mediastinitis me·di·as·ti·ni·tis (mē'dē-ās'tə-nī'tĭs)
Inflammation of the cellular tissue of the mediastinum.
inflammation of the tissue around the heart, aortic artery, and entrance (hilum) to the lungs, located in the middle chest cavity. The mediastinum is essentially the space between the left and right lung; it contains all the organs and major structures of the chest except the lungs themselves. Inflammation of the mediastinum can be caused by physical injuries, infections, or tumour growths.