What does a clean margin mean on a pathology report?

A clean margin — also called a negative margin — generally means no cancer cells were found at the outer edge of the tissue that was removed during a biopsy or surgery. Pathology reports often include margin status as one of the key details, alongside the type of cancer, its grade, and whether nearby lymph nodes were involved.

The opposite finding is a positive or "involved" margin, which means cancer cells were found at the edge of the removed tissue. This can matter for treatment planning, since it may affect the recommendation for additional surgery or other treatment.

If your report mentions margins and you're not sure what the finding means for your specific situation, it's a reasonable question to bring directly to your doctor: were the margins clean, and if not, what does that change about the plan going forward?

Pathology reports can appear in a patient portal before your doctor has discussed the results with you, so it's okay to wait for that conversation, or to reach out with questions if the wait feels long.