NCI Dictionary of Cancer Terms
The NCI Dictionary of Cancer Terms features 7,863 terms related to cancer and medicine.
Browse the dictionary by selecting a letter of the alphabet or by entering a cancer-related word or phrase in the search box.
- listen (MEE-dee-uh-STY-num)
- The area between the lungs. The organs in this area include the heart and its large blood vessels, the trachea, the esophagus, the thymus, and lymph nodes but not the lungs.