Dictionary of Cancer Terms
View in Spanish: Carcinoma in situ
Carcinoma in situ (KAR-sih-NOH-muh in SY-too)
A group of abnormal cells that remain in the place where they first formed. They have not spread. These abnormal cells may become cancer and spread into nearby normal tissue. Also called stage 0 disease.
Source: National Cancer Institute Dictionary of Cancer Terms, available at www.cancer.gov/dictionary.