A malignant breast lump and the lymph nodes it has spread to are removed. Is the tissue between these sites assessed for residual cancer cells?

Yes, the tissue between these sites is assessed for residual cancer cells. The pathologist will examine the surgical margins (the edge of the tissue that was removed) to make sure that all of the cancerous cells were removed. If any cancerous cells are found at the surgical margins, then more surgery may be needed to remove additional tissue.