Inside the Lumpectomy: What Really Happens in the  Operating Room

The operating room can feel abstract—you know surgery is happening, but not always what that truly means. Walking through the steps of a lumpectomy can help make the experience more understandable and easier to picture, so you feel oriented to what’s happening and why. The following is an example of what a patient experience may be. Results may vary.

Before You Even Drift Off

On the day of surgery, you’ll meet the team caring for you: nurses, your anesthesiologist, and your surgeon. Together, they review the plan, confirm which breast is being operated on, and answer any last-minute questions.
If a wire, seed, or magnetic marker was placed to guide the surgery, the team confirms everything is positioned correctly. Your surgeon has already reviewed your imaging and carefully planned the approach with your body and breast shape in mind.

Step 1: Gently Entering the Breast

Once you are asleep, your surgeon makes the planned incision. This may be directly over the area of concern or along a natural line or fold to support healing and appearance.

Using the “roadmap” created by imaging and localization tools, your surgeon carefully moves through the breast tissue to reach the tumor. The goal is precision—addressing what needs to be removed while protecting surrounding healthy tissue as much as possible.

Step 2: Removing the Tumor and a Margin

The tumor is removed along with a rim of surrounding tissue, called the margin. This creates a small buffer of healthy-appearing tissue around where the cancer was.
The removed tissue is then:

• Carefully marked so the pathologist knows which side is up/down and inside/outside
• Often imaged to confirm the tumor, and any markers are included

This careful orientation is what allows the pathology report to later describe margins in specific directions, such as toward the skin or chest wall.

Step 3: Shaping and Closing the Breast

After the tumor is removed, your surgeon turns attention to the shape of the breast. This is where oncoplastic techniques come in—reshaping the remaining tissue so the breast heals with a natural contour.
This may involve:

• Gently moving nearby tissue into the space left by the tumor
• Adjusting the surrounding tissue to support smooth healing
• Thinking ahead about balance with the other breast, if needed

This behind-the-scenes choreography is a thoughtful part of modern lumpectomy, even though you may never see it.

Step 4: Where LumiSystem™ May Be Used

At some hospitals, additional tools like LumiSystem™ are incorporated at this stage to provide real-time information during surgery.
Here’s how that may look:

• Before surgery, you will discuss whether LumiSystem is right for you. If you and your physician opt for using LumiSystem, you receive LUMISIGHT™ (pegulicianine), an optical imaging agent designed to respond to certain signals associated with cancer cells and nearby immune cells.
• After the tumor and margin are removed, the surgeon uses the LumiSystem camera to scan the lumpectomy cavity.
• Areas that give a signal may prompt a closer look and, in some cases, removal of additional tissue during the same operation.

LumiSystem does not replace standard lumpectomy techniques or final pathology. It is an added tool some surgeons use to support their goal of clear margins during surgery.

Safety Notes to Keep in Mind

Like all medical tools, LUMISIGHT™ and LumiSystem™ come with both benefits and risks. The most common side effects with LUMISIGHT (pegulicianine) are hypersensitivity and an abnormal color in urine. LUMISIGHT may cause serious hypersensitivity reactions, including anaphylaxis. Please see the LUMISIGHT Prescribing Information, including Boxed Warning, and Lumicell DVS Instructions for Use. For complete product information, visit www.LumiSystem.com.

It’s also helpful to remember:

• A signal does not always indicate cancer; noncancerous tissue can sometimes respond
• The absence of a signal does not guarantee that every cancer cell has been removed

Final treatment decisions are always guided by the full surgical plan, imaging, and pathology results.

Step 5: Finishing the Operation

Once your surgeon is satisfied with the removal and reshaping, the incision is closed with stitches under the skin and sometimes adhesive strips or surgical glue on the surface. A dressing or surgical bra may be placed to keep you comfortable and supported.
The tissue that was removed is sent to pathology, where specialists examine it carefully over the next several days. This is when details such as tumor size, margins, and other important features are confirmed.

Questions You Can Ask About the Operating Room

If you want to feel more oriented before surgery, these questions may help:

• Can you walk me through my lumpectomy step by step?
• Where will my incision be, and how are you thinking about how my breast will look afterward?
• Will localization tools like a wire or seed be used, and what should I expect?
• Is LumiSystem used at this hospital, and could it be part of my surgery?

To see how this fits into the larger picture—from planning to margins to recovery—you can visit the main lumpectomy page on Learn Look Locate, where everything is brought together in one place.

FAQs: Inside the Lumpectomy

Q1. How long does a lumpectomy usually take?
A: Surgery time varies, but many lumpectomies take one to two hours, depending on complexity and whether additional techniques are used.

Q2. Will I wake up with drains?
A: Most lumpectomies do not require drains, though your surgeon will explain if your situation is different.

Q3. Does tissue get checked during surgery?
A: Often, the removed tissue is imaged during surgery to confirm the tumor, and markers are included. Final margin results come from pathology after surgery.

Q4. Are oncoplastic techniques used for everyone?
A: Not always. Use depends on tumor location, breast size, and surgical goals, and your surgeon will discuss what’s appropriate for you.

Q5. Is LumiSystem used for all lumpectomies?
A: No. Use depends on hospital availability and whether the surgeon feels it may be helpful in a specific case.

Q6. What happens after surgery is finished?
A: You’ll recover in the post-anesthesia area, then go home the same day in most cases, with follow-up appointments scheduled to review pathology and next steps.

Important Safety Information

What is LUMISIGHT (pegulicianine) and Lumicell DVS?

• LUMISIGHT (pegulicianine) is an optical imaging agent, and Lumicell DVS is a fluorescence imaging device. LUMISIGHT and Lumicell DVS, in combination, are used in adults with breast cancer to help detect any remaining cancerous tissue at the surgical site following removal of the primary specimen during a lumpectomy procedure.

What is the most important information to know about LUMISIGHT?

• Hypersensitivity Reactions: LUMISIGHT may cause serious hypersensitivity reactions, including anaphylaxis. Anaphylaxis has occurred in 4/726 (0.6%) of patients in clinical studies. Tell your doctor if you have any history of hypersensitivity reactions to pegulicianine or to contrast media or products containing polyethylene glycol (PEG). Your healthcare provider should have emergency resuscitation drugs, equipment, and trained personnel available during the use of LUMISIGHT. Healthcare providers should monitor all patients for hypersensitivity reactions, and if one is suspected, immediately discontinue the injection and initiate appropriate therapy.
• The most common side effects (≥1%) include hypersensitivity and an abnormal color in urine.

What additional important information should I know about LUMISIGHT and Lumicell DVS?

• Adjunctive Use: Lumicell DVS is for use as part of the lumpectomy procedure and is not a replacement for the standard of care lumpectomy procedure and pathology.
• Risk of Misdiagnosis: The absence of a signal in surgery does not rule out cancer. Additionally, a positive signal may be seen in noncancerous tissue.
• Interference from Dyes Used for Sentinel Lymph Node Mapping: Your healthcare provider should avoid use of dyes before imaging the lumpectomy cavity in patients who have received LUMISIGHT.
• Other Risks: Using the Lumicell DVS handheld probe may cause tissue damage or infection.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit MedWatch or call 1-800-FDA-1088. Please see the LUMISIGHT Prescribing Information, including Boxed Warning, and Lumicell DVS Instructions for Use. For complete product information www.LumiSystem.com.