NCI Dictionary of Cancer Terms
The NCI Dictionary of Cancer Terms features 7,916 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 (MY-kroh-sfeer)
- A very tiny, hollow, round particle made from glass, ceramic, plastic, or other materials. Microspheres injected into blood vessels that feed a tumor may kill the tumor by blocking its blood supply. They can also be filled with a substance that may help kill more tumor cells.