In short
- Fat grafting leaves findings that are visible on imaging. That is a fact, not a suspicion.
- How often, in a review of 2,073 patients: oil cysts 6.5%, calcifications 4.5% and fat necrosis 1.2%.
- 🔑 And the practical consequence nobody publishes: 16.4% of patients were referred for additional imaging and 3.2% for a biopsy.
- ⚠️ The authors of that review conclude that those radiological changes, although frequent, do not appear to have any therapeutic consequence for patients.
- 🔑 And there is a comparison that puts the whole thing in perspective: in a blinded study with eight radiologists, fat grafting produced FEWER radiographic abnormalities than a breast reduction, with better BI-RADS scores and less aggressive follow-up.
- The findings from a graft have a characteristic appearance: an oil cyst with eggshell calcification is recognisably benign to an experienced radiologist.
- 🔑 And the conclusion from all of the above, said in full: fat grafting does not interfere with the detection of breast cancer. It leaves visible traces, yes; traces that are recognised as benign and that, what is more, become more clearly benign with time.
- ⚠️ The only thing you have to do: say that you have had a fat graft to the breast, and when. That is the piece of information that changes how the test is read.
- And one thing that does not change: breast cancer screening still applies to you.
There are two different worries around fat grafting to the breast and they get mixed up all the time:
- Can grafted fat encourage a cancer? — That is the oncological question, and it already has a published answer in the page on augmentation with your own fat: the largest meta-analysis, with 59 studies and 4,292 patients, found no increase in locoregional recurrence.
- Does it make a cancer harder to detect on a mammogram? — That is the imaging question, it is a different one, and it is the subject of this page. And the answer is worth giving up front, because it is reassuring: it does not interfere with detecting a possible cancer. What it does is leave findings of its own, characteristically benign in appearance, that the radiologist has to know how to interpret — and for that, telling them is enough.
Why fat grafting shows on a mammogram
When fat is grafted into the breast, part of it takes and integrates as normal fatty tissue, indistinguishable from the rest. And part of it does not survive.
What happens to the part that does not take is what shows up afterwards:
- The oil cyst. A collection of liquefied fat that becomes encapsulated. In time, its wall may calcify, forming an eggshell calcification, characteristically benign.
- Fat necrosis. Fatty tissue that has become necrotic and organises itself, sometimes forming a palpable lump.
- Calcifications. Calcium deposits that appear in that repair process, usually scattered and benign in shape.
🔑 None of this is unique to fat grafting. Fat necrosis and calcifications also appear after a breast reduction, after a biopsy, after breast-conserving cancer surgery and after a simple blow to the breast. They are the trace left by fat repairing itself, whatever caused it.
How often they appear
A systematic review gathered 22 studies with 2,073 patients having aesthetic augmentation with fat, including only consecutive patient series:
| Radiological finding | Frequency |
|---|---|
| Oil cysts | 6.5% |
| Calcifications | 4.5% |
| Fat necrosis | 1.2% |
And the practical consequences, which are what really affect a person:
- ⚠️ Risk of being referred for additional imaging to rule out malignant change: 16.4%.
- ⚠️ Risk of being referred for a biopsy: 3.2%.
The authors’ conclusion: the rates of radiological change after fat grafting are high, but those changes do not appear to have any therapeutic consequence for patients.
🔑 Translated into what happens to a person: roughly one in six will at some point get a call to extend or repeat a test, and the vast majority of those calls will come to nothing. It is not a medical complication and it is a fright and another appointment. It deserves to be known before deciding.
The comparison that puts it in perspective
It is the best argument available and nobody publishes it.
The design. Twenty-seven women with normal previous mammograms underwent fat grafting to the breast for cosmetic purposes, with a mean injected volume of 526.5 cc per patient, and the mammogram was repeated at 12 months. Post-operative mammograms from 23 breast reduction patients were used as a control group.
Eight breast radiologists reviewed each mammogram blind, without knowing which group it belonged to.
The results:
- No significant differences between the two groups in oil cysts, benign calcifications and calcifications prompting biopsy.
- ⚠️ Scarring and masses requiring biopsy were significantly more frequent in the breast reduction group (p < 0.001 in both cases).
- BI-RADS scores were higher after breast reduction (p < 0.001) — that is, worse.
- And the radiologists recommended more aggressive follow-up in the reduction group (p < 0.01).
The authors’ conclusion: compared with reduction mammoplasty, a widely accepted procedure, fat grafting to the breast produces fewer radiographic abnormalities, with a more favourable BI-RADS score and less aggressive follow-up recommendations.
🔑 That is the context missing every time interference with imaging is presented as an argument against lipofilling. Nobody advises against a breast reduction on account of its radiological findings.
⚠️ And the limits, which have to be stated: it is 27 patients against 23, with 12-month follow-up. The authors also observed consistent differences in interpretation between individual radiologists, which is a useful reminder that these readings also depend on who makes them.
What you have to do
It is short and it is the only thing that matters.
1. Always say so. When you request or attend any breast imaging — mammogram, ultrasound, MRI — say that you have had a fat graft to the breast.
2. Say when. The date of the surgery guides interpretation a great deal, because the findings evolve: the images tend to look more clearly benign with time, as the oil cysts develop their wall calcification.
3. Take your operation note if you have it. Knowing how much fat was grafted and into which areas helps.
4. Resume your check-ups. This is the point that must not be lost, and here is what is recommended: go back to breast check-ups after the graft, so as to have a new baseline to compare against in the years that follow. And above that, the breast cancer screening programme applies to you according to your age and your history, whether you have had a graft or not.
⚠️ And if you are called back for further imaging, do not panic. With a history of fat grafting, that call is rather more likely than in the general population, and the vast majority of those extra tests find nothing.
What this page does NOT say
It does not say that fat grafting is unsafe from an oncological point of view. The largest meta-analysis available, with 59 studies and 4,292 patients followed up, found no increase in locoregional recurrence. That analysis is set out in the page on augmentation with your own fat, with the qualification that the setting there is reconstruction after a cancer, which is where it has been studied most.
It does not say that it makes cancer harder to diagnose. It says that it produces findings that have to be interpreted, that the available comparison places them below those of a breast reduction, and that the information that changes that interpretation is what you give by mentioning your history.
And a note on implants
In case you are comparing the two options: the implant has its own column in this chapter too.
It covers part of the tissue on a conventional mammogram, which makes specific displacement views necessary; and the FDA warns that calcifications forming around an implant can be mistaken for a cancer and prompt additional surgery.
That is to say: both techniques leave a trace on imaging, in different ways. It is compared in the page that sets implants against your own fat and set out in detail in the one on living with implants.
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Frequently asked questions
Does breast lipofilling make breast cancer harder to detect?
It leaves findings a radiologist has to interpret — oil cysts, calcifications, fat necrosis — and in a blinded study with eight radiologists those findings were less troublesome than those of a breast reduction, with better BI-RADS scores. What does matter is that you mention your history.
What shows on a mammogram after a fat graft?
Mainly oil cysts — collections of encapsulated liquefied fat whose wall may calcify, forming a characteristically benign eggshell appearance — and scattered calcifications. Less often, fat necrosis.
How many patients end up having extra tests?
In a review of 2,073 patients, 16.4% were referred for additional imaging and 3.2% for a biopsy. The authors point out that those changes do not appear to have therapeutic consequences.
Do those findings disappear with time?
They do not disappear, but they tend to look more clearly benign as the years pass, mainly because of the wall calcification of the oil cysts.
Do I have to stop having mammograms?
Quite the opposite. Screening still applies to you according to your age and your history. What changes is that you must mention your graft and when it was done.
Which is worse for check-ups, lipofilling or an implant?
Both leave a trace, in different ways. The implant covers tissue and makes specific views necessary; the fat graft leaves findings that have to be interpreted. Neither option takes you out of screening.
And the risk of the fat causing a cancer?
That is a different question and it has its answer: the largest meta-analysis, with 59 studies and 4,292 patients, found no increase in locoregional recurrence. It is set out in the page on augmentation with your own fat.
Sources
- Ørholt M, et al. Complications after Breast Augmentation with Fat Grafting: A Systematic Review. Plastic and Reconstructive Surgery, 2020. PMID 32097306. — 22 studies with 2,073 cosmetic fat grafting augmentation patients, including only consecutive patient series: radiological changes with oil cysts in 6.5%, calcifications in 4.5% and fat necrosis in 1.2%; a 16.4% risk of referral for additional imaging and a 3.2% risk of referral for biopsy; the authors conclude that the rates of radiological change are high but that those changes do not appear to have any therapeutic consequence for patients.
- Rubin JP, et al. Mammographic changes after fat transfer to the breast compared with changes after breast reduction: a blinded study. Plastic and Reconstructive Surgery, 2012. PMID 22261561. — 27 women with normal pre-operative mammograms treated with breast fat grafting for cosmetic purposes, with a mean injected volume of 526.5 cc, and mammograms repeated at 12 months; control group of 23 reduction mammoplasty patients; eight breast radiologists reviewed each mammogram blind: no significant differences in oil cysts, benign calcifications and calcifications prompting biopsy; scarring (p < 0.001) and masses requiring biopsy (p < 0.001) significantly more frequent in the reduction cohort; higher BI-RADS scores after reduction (p < 0.001) and more aggressive follow-up recommendations (p < 0.01); consistent differences in interpretation between individual radiologists were observed.
- Risks and Complications of Breast Implants. U.S. Food and Drug Administration, updated 14 December 2023. fda.gov. — Calcifications or calcium deposits around the implant are described as “hard lumps under the skin around the implant” that “can be mistaken for cancer during a mammogram, resulting in additional surgery”.
Book your consultation
If you are considering a fat graft to the breast and you are worried about what will happen to your check-ups, it is a specific conversation with an answer. At our practice in Valencia we explain which findings are to be expected, how likely it is that you will be called back for further imaging and what information it is worth taking with you when that happens.
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