What happens in the main operation for melanoma, how the margin width is chosen from tumor thickness, and what recovery and the final pathology report involve.
A biopsy that shows melanoma is usually followed by a second, larger operation called a wide local excision. The surgeon removes the biopsy site together with a rim of normal-looking skin around it and the fat beneath it. For most people with early melanoma, this operation is the main treatment, and often the only one needed.
The biopsy exists to make the diagnosis. It tells the pathologist how thick the melanoma is, and it may even remove all of the visible tumor. Melanoma cells can still sit in the nearby skin where no one can see them.
Taking a safety rim of normal skin, called the margin, lowers the chance that the melanoma grows back in the same spot. The American Cancer Society lists wide excision as the standard treatment for melanomas from stage 0 through stage II.
Margin width follows Breslow thickness, the measurement in millimeters from the top of the melanoma to its deepest point. Thicker tumors get wider margins. Guidelines from the National Comprehensive Cancer Network (NCCN), which most US surgeons follow, recommend these margins:
The surgeon measures these distances on the skin at the time of surgery, outward from the edge of the biopsy scar or any leftover pigment. A 1 cm margin on every side, plus the scar itself, makes a wound several centimeters across. Many people expect something smaller.
Depth counts as well. The surgeon usually removes the fat under the melanoma down to the fascia, the tough sheet that covers the muscle, and leaves the fascia in place.
The numbers can bend for anatomy. On an eyelid, a finger, or the sole of a foot, a full 2 cm could cost the use of that part, and the guidelines let surgeons narrow the margin in those places.
Most wide excisions happen under local anesthesia. You are awake, the area is numbed with injections, and you go home the same day.
Melanomas thicker than about 1 mm, and some thinner ones with higher-risk features, often call for a sentinel lymph node biopsy. Surgeons do that test in the same session as the wide excision, usually in an operating room with sedation or general anesthesia. Removing a wide patch of skin first can change the lymph drainage that the test depends on, which is why the 2 procedures are paired.
After marking the margin with a ruler, the surgeon extends the outline into an ellipse, a shape like a football that is roughly 3 times as long as wide. The extra length lets the skin edges meet in a flat line instead of bunching at the ends. Your scar will therefore be a good deal longer than the original spot.
Most wounds close side to side with 2 layers of stitches: dissolving stitches in the deep tissue and surface stitches, staples, or skin glue on top.
Skin on the shin, scalp, foot, and hand has little give. There the surgeon may shift a flap of neighboring skin into the gap or lay a skin graft, a thin sheet of skin taken from another part of your body.
Melanoma in situ on sun-damaged facial skin, often the lentigo maligna type, tends to spread wider under the surface than it looks. A standard ellipse can miss the edges, or it can take more of a nose or eyelid than necessary.
Some centers handle these cases with Mohs surgery or a staged excision, in which the edges are checked under the microscope before the wound is closed. The American Cancer Society notes that Mohs surgery is outside standard melanoma care but can be an option for some very early melanomas on the face or ears.
Expect soreness for several days, usually handled with acetaminophen. Swelling and bruising peak around day 3 or 4. Surface stitches come out in about 1 to 2 weeks, sooner on the face and later on the back and legs.
Tension is the enemy of a healing wound. Your team will ask you to hold off on heavy lifting, running, and stretching that pulls across the scar for a few weeks, longer for wounds on the back or over a joint.
Call the surgeon's office for bleeding that continues after 20 minutes of firm, steady pressure, for redness that spreads, for pus, or for fever. The scar will look red and firm at first. It softens and fades over about 12 months.
All of the removed tissue goes to a pathologist. The report answers 3 questions: whether any melanoma remained after the biopsy, whether the edges of the specimen are free of melanoma, and whether any leftover tumor is thicker than the biopsy showed.
Most reports show clear margins, and many show no remaining melanoma at all. Occasionally the pathologist finds melanoma at an edge, and the surgeon goes back to take more skin. Rarely, a deeper leftover portion raises the Breslow thickness and changes the stage.
Results take about 1 to 2 weeks. Keep copies of both reports, the biopsy and the excision. Every doctor who follows you later will want the Breslow thickness from the first and the margin status from the second.
