Why is there a dent in my breast after lumpectomy?

A dent in the breast after lumpectomy is the mark of tissue that was removed and never replaced, made more visible and firmer by radiation. It is one of the most common things we are asked about by women who were treated for breast cancer with lumpectomy, often years ago. They did well, the cancer treatment worked, and they are survivors. What persists is a breast that did not fill in evenly, leaving a dent or a depression. Many were told, or assumed, that nothing can be done, and some believe it is simply the price of their survival.

That is not always true. Reconstruction after lumpectomy can be more demanding than reconstruction after mastectomy, largely because of radiation, but we have a number of tools for these problems, and in the right patient, with the right operation, the result can change how a woman feels in her clothes and in her own skin.

What causes a dent after lumpectomy

A lumpectomy removes the tumor with a margin of healthy breast tissue around it, and the space left behind is filled by scar rather than by breast. Where the removed tissue was small relative to the breast, or sat in the deeper tissue, the surrounding breast usually fills the gap and the surface stays smooth. Where it was large, or sat close to the skin, or was taken from a part of the breast with little tissue to spare, there is a greater chance that the surface sinks into the space below it. That sinking is the dent.

Radiation usually worsens it. Radiation therapy after lumpectomy is standard, and it works by damaging the ability of cells to divide, which affects healing tissue as well as any remaining cancer cells. The treated breast develops fibrosis, which is permanent scarring with reduced blood flow, and fibrosis contracts. Over the first one to two years after treatment the scar tightens, the skin tethers to the chest wall or to the deeper scar, and the breast can shrink and pull upward. A dent that appeared minor at the end of radiation often looks worse at two years, which is why many women notice it long after their oncology visits have become routine.

What kind of dent you have decides what can be done

The most important step is to classify the problem, because the treatment follows from the size and location of the defect and the quality of the tissue around it, and surgeons have grouped the patterns seen after breast conservation in just this way (Clough, 1998). If the treated breast has a reasonable shape but is smaller or higher than the other side, improving symmetry may mean lifting or reducing the other breast. If there is a localized hollow or a pulled scar, the plan may involve replacing volume, releasing scar tissue, or both.

When the damage is extensive, a limited repair may not be enough, and a more substantial reconstruction may need to be discussed. That is a different situation from an isolated dent.

The examination should explain which problem you have and why the proposed operation addresses it. Your goals matter, but so do skin quality, blood supply, available donor tissue, and the risks of healing.

Fat grafting and what it can and cannot do

Fat grafting fills a dent with the patient's own fat, taken by liposuction from the abdomen or thighs and injected in small amounts into the sunken area.

Radiation and dense scarring make the result less predictable, but they do not mean fat grafting cannot help. Transferred fat survives only where it is surrounded by living tissue with a good blood supply, so in a tightly scarred dent more of the fat is reabsorbed and the dent can return. In one single-center retrospective series, fat grafting improved lumpectomy defects with relatively few complications; some patients needed further procedures, and some underwent biopsies for imaging findings that proved benign (Mann, 2018). Fat grafting can produce fat necrosis, oil cysts, or calcifications, which may need assessment during breast surveillance, and your imaging team should know what was done.

The question that matters is whether fat alone can address your particular defect. A substantial dent with tightly tethered skin usually needs more than added volume.

Local perforator flaps for the dents fat cannot fix

For a deeper or more fibrotic dent, the reliable strategy is to move living tissue into the space, replacing what the lumpectomy took. A local perforator flap takes skin and fat from the side of the chest, the upper back, or the inner chest near the breastbone, keeps it attached to a single small artery and vein (the perforator), and rotates it into the dent. The three we use most are the intercostal artery perforator flap (ICAP) from the lateral chest, the thoracodorsal artery perforator flap (TDAP) from the upper back, and the internal mammary artery perforator flap (IMAP) from the chest near the sternum. The approach was described two decades ago (Hamdi, 2004), and the scars are designed to sit in the bra line or the fold of the breast. In a small case series of delayed local perforator flaps, most of them after lumpectomy and radiation, there were no flap losses and further revision was uncommon (Quinn, 2020). Despite their complexity, these are ambulatory operations with relatively short recoveries. They require microsurgical skill and training, which is why they are offered less often, and part of why so many women are told nothing can be done.

Sometimes the right advice is to leave it alone

Some dents should not be operated on. If the dent is shallow, if it does not show in clothing, if the skin over it is soft, or if the radiation damage is severe enough that any incision risks a wound that will not heal, the best advice is to leave the treated breast alone. In those cases the useful conversation is often about the other breast, where a lift or a modest reduction can restore symmetry without touching radiated tissue at all. That can be a disappointing conversation, but it is an honest one given the techniques available today.

What to ask

A useful breast reconstruction opinion explains the likely benefit, the limitations, and the option of doing nothing. These questions make the plan concrete:

1. What is causing the change in my breast?
2. What can the proposed operation realistically improve?
3. Where will the scars be, and how many procedures might I need?
4. What happens if I choose no surgery?

The answers are a clinical opinion rather than a verdict, and the person who decides whether the result worked is you.

Related: Breast reconstruction after lumpectomy, Fat grafting after breast reconstruction, Breast reconstruction after radiation.

References

Clough KB, Cuminet J, Fitoussi A, Nos C, Mosseri V. Cosmetic sequelae after conservative treatment for breast cancer: classification and results of surgical correction. Annals of Plastic Surgery. 1998;41(5):471-481. doi:10.1097/00000637-199811000-00004

Hamdi M, Van Landuyt K, Monstrey S, Blondeel P. Pedicled perforator flaps in breast reconstruction: a new concept. British Journal of Plastic Surgery. 2004;57(6):531-539. doi:10.1016/j.bjps.2004.04.015

Mann RA, Ballard TNS, Brown DL, Momoh AO, Wilkins EG, Kozlow JH. Autologous fat grafting to lumpectomy defects: complications, imaging, and biopsy rates. Journal of Surgical Research. 2018;231:316-322. doi:10.1016/j.jss.2018.05.023

Quinn EM, O'Ceallaigh S, Highton L, Murphy J. The use of local perforator flaps in delayed or secondary breast reconstruction. Plastic and Reconstructive Surgery Global Open. 2020;8(12):e3263. doi:10.1097/GOX.0000000000003263

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