A resection margin or surgical margin is the margin of apparently non-tumorous tissue around a tumor that has been surgically removed, called " resected", in

surgical oncology Surgical oncology is the branch of surgery applied to oncology; it focuses on the surgical management of tumors, especially cancerous tumors. As one of several modalities in the management of cancer, the specialty of surgical oncology has evolved ...

. The resection is an attempt to remove a

cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...

tumor A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

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 Pathology is the study of the causal, causes and effects of disease or injury. The word ''pathology'' also refers to the study of disease in general, incorporating a wide range of biology research fields and medical practices. However, when us ...

to see if the margin is indeed free from tumor cells. If cancerous cells are found at the edges the operation is much less likely to achieve the desired results. Residual tumour at the primary site after treatment (it does not address the surgical margin as commonly believed) is classified by the pathologist as (AJCC 8th Edition): * R0 - no cancer cells seen microscopically at the primary tumour site. * R1 - cancer cells present microscopically at the primary tumour site. * R2 - Macroscopic residual tumour at primary cancer site or regional lymph nodes. It does not include metastatic disease identified but not sampled at the time of surgery. The Margin Status following tumour resection (AJCC 8th Edition): * Negative margin: No tumour at the margin. * Microscopic positive margin: Tumour identified microscopically at the margin. * Macroscopic positive margin: Tumour identified grossly at the margin. * Margin not assessed. The size of the margin is an important issue in areas that are functionally important (i.e., large vessels like the

aorta The aorta ( ) is the main and largest artery in the human body, originating from the left ventricle of the heart and extending down to the abdomen, where it splits into two smaller arteries (the common iliac arteries). The aorta distributes ...

or vital organs) or in areas for which the extent of surgery is minimized due to aesthetic concerns (i.e.,

melanoma Melanoma, also redundantly known as malignant melanoma, is a type of skin cancer that develops from the pigment-producing cells known as melanocytes. Melanomas typically occur in the skin, but may rarely occur in the mouth, intestines, or eye ( ...

of the face or

squamous cell carcinoma Squamous-cell carcinomas (SCCs), also known as epidermoid carcinomas, comprise a number of different types of cancer that begin in squamous cells. These cells form on the surface of the skin, on the lining of hollow organs in the body, and on the ...

of the

penis A penis (plural ''penises'' or ''penes'' () is the primary sexual organ that male animals use to inseminate females (or hermaphrodites) during copulation. Such organs occur in many animals, both vertebrate and invertebrate, but males do n ...

). The desired size of margin around the tumour can vary. In resections for

breast cancer Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, milk rejection, fluid coming from the nipple, a newly inverted nipple, or a re ...

, there appears to be a difference between European and American radiation oncologists, with the former preferring larger margins of over 5 mm. Apart from traditional methods looking at stained "shaves" (thin slices of tissue removed from the edge of the margin) or smeared and stained imprints, more recent techniques used to assess margins include x-rays with compression, frozen specimens, and new techniques such as intraoperative fluorescence imaging,

Raman spectroscopy Raman spectroscopy () (named after Indian physicist C. V. Raman) is a spectroscopic technique typically used to determine vibrational modes of molecules, although rotational and other low-frequency modes of systems may also be observed. Raman sp ...

optical coherence tomography Optical coherence tomography (OCT) is an imaging technique that uses low-coherence light to capture micrometer-resolution, two- and three-dimensional images from within optical scattering media (e.g., biological tissue). It is used for medical ...

and quantitative diffuse reflectance

spectroscopy Spectroscopy is the field of study that measures and interprets the electromagnetic spectra that result from the interaction between electromagnetic radiation and matter as a function of the wavelength or frequency of the radiation. Matter wa ...

Definition

Surgical margin in a surgery report defines the visible margin or free edge of "normal" tissue seen by the

surgeon In modern medicine, a surgeon is a medical professional who performs surgery. Although there are different traditions in different times and places, a modern surgeon usually is also a licensed physician or received the same medical training as ...

with the naked eye. Surgical margin as read in a

pathology Pathology is the study of the causes and effects of disease or injury. The word ''pathology'' also refers to the study of disease in general, incorporating a wide range of biology research fields and medical practices. However, when used in ...

report defines the histological measurement of normal or unaffected tissue surrounding the visible

under a

microscope A microscope () is a laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic means being invisibl ...

on a glass mounted histology section. 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 Bread loafing is a common method of processing surgical specimens for histopathology. The process involves cutting the specimen into 3 or more sections. The cut sections are mounted by embedding in paraffin or frozen medium. The cut edge is then t ...

technique suggests that residual cancer might be left due to

false negative A false positive is an error in binary classification in which a test result incorrectly indicates the presence of a condition (such as a disease when the disease is not present), while a false negative is the opposite error, where the test result ...

error. A surgeon often will perform a second surgery if a narrow surgical margin is noted on a pathology report.

Associated errors and recurrence rate

This determination is made with the full understanding of "

error" intrinsic in the

technique of histology (also known as POMA - a term used by the NCCN). The higher the false negative error is, the higher the recurrence rate of a cancer or tumor at the surgical margin. This is due to the misreading of a pathology specimen as being clear of residual tumor when there is actually residual tumor left where the specimen was not cut and mounted on the histology slide. The "

error" is very low in the

CCPDMA Complete circumferential peripheral and deep margin assessment (CCPDMA) is the preferred method for the removal of certain cancers, especially skin cancers. There are two forms of CCPDMA surgery: Mohs surgery and surgical excision coupled with mar ...

method of histology processing, and can be very high in the

(POMA) method of histology processing. In the bread loafing method of processing, one will note a high

error rate with narrow surgical margin; and one will note a low

error with a wide surgical margin Surgical margin has a much less significant effect on the

error rate of

methods, allowing the surgeon to routinely use very narrow surgical margins (1 to 2 mm for non-melanoma skin cancer). The worldwide extent of inadequate resection of the tumor is illustrated in following Table showing the percentage of positive surgical margins for the most common cancer types.

References

External links

Surgical Considerations: Margins
Surgical oncology

Definition

Associated errors and recurrence rate

References

Further reading

External links