resection margin

A resection margin is the margin of apparently non-tumerous tissue around a tumor that has been surgically removed, called "resected", in surgical oncology. The resection is an attempt to remove a cancer tumor so that no portion of the malignant growth extends past the edges or margin of the removed tumor and surrounding tissue. These are retained after the surgery and examined microscopically by a pathologist. If cancerous cells are found at the edges the operation is much less likely to achieve the desired results.[1]

Margins are classified by the pathologist as:
R0 - no cancerous cells seen microscopically; this is the desired result
R1 - cancerous cells can be seen microscopically
R2 - even gross examination by the naked eye shows tumor tissue on the margin, indicating more remains on the patient.

R0 is also called "clean", "tumor negative" or "negative margin"; R1 and R2 are "tumor positive".[2] The presence of abnormal cells that are not part of the main tumor, such as lymphatic invasion, atypical ductal hyperplasia or lobular carcinoma in situ in breast tissue, may not prevent a margin being graded as R0.[2]

The size of the margin is an important issue in areas that are functionally important (i.e. large vessels like the aorta or vital organs), or in areas for which the extent of surgery is minimized due to aesthetic concerns (i.e. melanoma of the face or squamous cell carcinoma of the penis).[3]

https://en.wikipedia.org/wiki/Resection_margin




Also see 'surgical margin'

Surgical margin, also known as tumor free margin, free margin, normal skin margin, and normal tissue margin, usually refers to the visible normal tissue or skin margin that is removed with the surgical excision of a tumor, growth, or malignancy.

Surgical margin in a surgery report defines the visible margin or free edge of "normal" tissue seen by the surgeon with the naked eye. Surgical margin as read in a pathology report defines the histological measurement of normal or unaffected tissue surrounding the visible tumor under a microscope on a glass mounted histology section.[1][2] A "narrow" surgical margin implies that the tumor exists very close to the surgical margin, and a "wide" surgical margin implies the tumor exists far from the cut edge or the surgical margin. Narrow surgical margin using the bread loafing technique suggests that residual cancer might be left due to false negative error. A surgeon often will perform a second surgery if a narrow surgical margin is noted on a pathology report.

https://en.wikipedia.org/wiki/Surgical_margin