The surgical margin is the delineation of healthy tissue after the removal of the tumor by surgery, and it is necessary to determine if all tumor cells have been completely removed.
To do this, the pathologist examines the edges of the tissue removed during surgery under a microscope. This observation defines the surgical margin:
- In cases where there are no tumor cells near the edges of the removed tissue, the margins are classified as negative;
- In cases where there are tumor cells near the edges of the removed tissue, the margins are classified as close;
- In cases where there are tumor cells at the edge of the removed tissue, the margins can be classified as focally involved or positive, depending on the extent of tumor presence at the edges.
Learn more about the safety margin and tumor removal in oncologic surgery.
