Skip to main content
An official website of the United States government
Español

cancer of unknown primary origin

(KAN-ser ... UN-none PRY-mayr-ee OR-ih-jin)
A case in which cancer cells are found in the body, but the place where the cells first started growing (the origin or primary site) cannot be determined. Also called carcinoma of unknown primary and CUP.
Search NCI's Dictionary of Cancer Terms