WLE stands for wide local excision, a surgery that removes a tumor along with a surrounding rim of healthy tissue. The goal is to eliminate all cancer cells while preserving as much normal tissue as possible. It’s one of the most common procedures for treating skin cancer (especially melanoma) and breast cancer, though it can be used for other types of tumors as well.
How the Procedure Works
A wide local excision is relatively straightforward compared to many cancer surgeries. The area around the tumor is cleaned and draped with sterile towels, then numbed with a local anesthetic. For breast procedures or deeper tumors, general anesthesia may be used instead. The surgeon cuts out the tumor and a margin of normal-looking tissue around it, typically in a football-shaped ellipse for skin cancers. That tissue is sent to a lab where a pathologist examines the edges under a microscope to confirm all the cancer was removed.
Once the tissue is out, the wound is closed with stitches. In most cases the edges of the skin can simply be pulled together. In areas where skin is tight, like the scalp, a skin graft or flap may be needed to close the gap.
Margin Size Depends on the Cancer
The “wide” in wide local excision refers to the margin of healthy tissue removed around the visible tumor. How wide that margin needs to be varies significantly depending on the type and depth of cancer being treated.
Melanoma Margins
For melanoma, margin guidelines are based on how deep the tumor has grown into the skin, measured in millimeters. The National Comprehensive Cancer Network and the American Academy of Dermatology recommend:
- Melanoma in situ (confined to the top layer of skin): 0.5 to 1 cm margin
- Tumors less than 1 mm thick: 1 cm margin
- Tumors 1 to 2 mm thick: 1 to 2 cm margin
- Tumors thicker than 2 mm: 2 cm margin
These numbers might sound small, but on the skin, a 2 cm margin in every direction means removing a significant circle of tissue. The wider margins for thicker melanomas reflect the greater chance that cancer cells have spread microscopically beyond the visible edges of the tumor.
Breast Cancer Margins
For invasive breast cancer, the standard for a clear margin is simpler: no tumor cells touching the inked edge of the removed tissue (called “no ink on tumor”). For ductal carcinoma in situ (DCIS), a non-invasive form of breast cancer, guidelines call for at least a 2 mm margin when radiation therapy follows surgery. Margins wider than 2 mm for DCIS haven’t been shown to further reduce the risk of the cancer coming back, so surgeons generally don’t aim for more than that.
Why Margins Matter So Much
After the tissue is removed, the pathologist paints the edges with ink and slices the specimen into thin sections. The margin report is one of the most important parts of your results. Margins are typically described as clear (no cancer near the edge), close (cancer cells near but not at the edge), or positive/involved (cancer cells right at the inked edge).
The difference is clinically significant. In breast cancer, having tumor cells at the inked margin is associated with nearly five times the risk of the cancer returning in the same area compared to having clear margins. If margins come back positive, you’ll likely need a second surgery to remove more tissue. Even after that re-excision, the risk of local recurrence remains somewhat elevated compared to getting clear margins the first time, which is why surgeons aim to get it right in one operation.
WLE for Breast Cancer: What Else Happens
When WLE is used for breast cancer, it’s the surgical centerpiece of what’s called breast-conserving therapy. The surgery preserves the breast rather than removing it entirely. In most cases, radiation therapy follows to treat any microscopic cancer cells that might remain in the surrounding breast tissue.
If you have invasive breast cancer, the surgeon will typically check your lymph nodes at the same time as the excision. This is done through a sentinel lymph node biopsy, where a dye or tracer is injected near the tumor to identify the first lymph node(s) that drain from that area. Those nodes are removed and checked for cancer cells. If they’re clear, no further lymph node surgery is needed. Clinical trials have confirmed that this targeted approach is sufficient for staging breast cancer and preventing regional recurrence, sparing patients the more extensive lymph node removal that was once standard.
For larger tumors or tumors in certain locations (particularly the lower part of the breast), removing enough tissue can distort the breast’s shape. A complication sometimes called “bird’s beak deformity” can develop, where the lower part of the breast shrinks and the nipple shifts downward. Oncoplastic techniques, which blend cancer surgery with plastic surgery principles, can address this by reshaping the remaining breast tissue during the same operation. These approaches pay attention to incision placement, breast symmetry, and the position of the nipple to achieve a more natural result.
Recovery After WLE
For skin cancer excisions done under local anesthesia, recovery is relatively quick. You’ll keep the wound covered for the first 24 to 48 hours, then gently clean it with cool water and soap. Stitches stay in place for one to three weeks depending on the location. The key restriction is avoiding strenuous activity that could pull the wound open, particularly in the first week or two.
Recovery from a breast WLE takes longer. Soreness and swelling around the surgical site are normal for the first couple of weeks. Most people return to light daily activities within a few days but are advised to avoid heavy lifting or vigorous upper-body exercise for several weeks. If lymph nodes were also removed, recovery may take a bit longer, and your surgical team will give you specific guidance about arm movement and activity.
Possible Complications
WLE is generally a low-risk surgery, but complications can occur. The most common issue after breast WLE is seroma, a pocket of clear fluid that collects in the space left by the removed tissue. Seroma rates after breast surgery vary widely, and small fluid collections often resolve on their own. Larger ones may need to be drained with a needle, sometimes more than once.
Other potential complications include hematoma (a collection of blood under the skin, usually noticeable as a firm, bruised area), wound infection, and delayed healing. Scarring is inevitable with any surgery, and the final appearance of the scar depends on the size and location of the excision, how your body heals, and whether radiation follows. Radiation can increase scar firmness and contracture over time.
When a Second Surgery Is Needed
The most common reason for a second procedure is positive or close margins on the pathology report. If cancer cells are found at the edge of the removed tissue, a re-excision takes out additional tissue from that area. In breast cancer, the re-excision rate varies by surgeon and tumor characteristics, but it’s not uncommon. Some patients ultimately need a mastectomy if clear margins can’t be achieved after one or two attempts at re-excision, though this outcome is relatively rare.
For melanoma, a WLE is often the second surgery a patient has. The initial procedure is usually a diagnostic biopsy that confirms the melanoma diagnosis and measures its depth. The WLE then follows, removing a wider margin around the biopsy scar based on the thickness guidelines. A sentinel lymph node biopsy may be done at the same time for melanomas thicker than about 1 mm.