NCI Dictionary of Cancer Terms
The NCI Dictionary of Cancer Terms features 7,800 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 (in-TRA-vuh-SAY-shun)
- The movement of a cell or a foreign substance through the wall of a blood or lymph vessel into the vessel itself. In cancer, this is how cancer cells pass through a vessel wall and enter the blood or lymph systems. It is one way that cancer spreads in the body.