Carcinoma in situ is cancer in the early stage before invading surrounding tissue.
Pronunciation
(kar-si-NŌ-ma) (in) (SĪ-too)
Other names for carcinoma in situ are stage 0 disease, non-invasive cancer, or pre-invasive cancer.
Definition, Pronunciation and history box from: Exploring Medical Language Edition 10, Chapter 2 Body Structure, Color, and Oncology, p. 43