The extent of invasion of malignant cells into surrounding tissues can really only be defined by excision, as the measurement exists on a cellular level. IN GENERAL doctors attempt to describe invasion in terms which cannot be held to these strict parameters. For instance a carcinoma in situ, is a VERY localized cancer that is at it's earliest stages and which has not invaded deeply into surrounding structures or advanced by any other means from the immediate area. Even this description is vague, causing different pathologists to even disagree in to how far through the various levels of epithelium it can extend and still be called "in situ

Brian, stage 4 oral cancer survivor. OCF Founder and Director. The first responsibility of a leader is to define reality. The last is to say thank you. In between, the leader is a servant.