In short. Under-correction is the commonest disappointment and calcification the most consequential risk. Sorting breast fat transfer complications by what they mean for you.
Key points
- Transferred fat can calcify, and calcification is one of the findings breast screening looks for.
- Benign calcification after fat transfer can resemble, or obscure, changes that warrant investigation, which means mammography becomes harder to read and may lead to extra imaging or a biopsy to be certain.
- This does not mean the surgery causes cancer; it means it makes surveillance less clear.
The complications of breast fat transfer are worth sorting by what they actually mean. Under-correction is the most common disappointment. Irregularity is the most common visible problem. Calcification is the most consequential in the long term, because it affects your screening for years. Infection and bleeding are uncommon and usually manageable.
Under-correction and irregularity
Under-correction is not a complication in the surgical sense, but it is the commonest reason patients are unhappy, because less fat survived than was hoped. Irregularity — palpable lumps, unevenness, a surface that looks bumpy in some lights — is the commonest visible problem, and it is more likely where fat was placed in large deposits or where the tissue cover is thin. Most lumps soften over the first months; some persist.
Fat necrosis and oil cysts
Fat that does not establish a blood supply dies, and dead fat is replaced by oil and scar tissue. That can form an oil cyst or a firm area. Some resolve without treatment, some are aspirated with a needle, and occasionally removal is needed. Fat necrosis is a recognised consequence of the operation rather than a sign that something was done badly, though its likelihood is affected by how the fat is placed.
Calcification is the risk with the longest shadow
Transferred fat can calcify, and calcification is one of the findings breast screening looks for. Benign calcification after fat transfer can resemble, or obscure, changes that warrant investigation, which means mammography becomes harder to read and may lead to extra imaging or a biopsy to be certain. This does not mean the surgery causes cancer; it means it makes surveillance less clear. It should be discussed before surgery, not discovered afterwards.
Infection, bleeding and the donor site
Infection is uncommon and usually treatable, occasionally requiring drainage. Bleeding and bruising occur at both sites, and a collection of blood may need attention. The donor site has its own complications: prolonged soreness, numbness, contour irregularity where fat was taken, and a permanent scar. These are usually minor but are frequently underestimated beforehand.
The rare risks and the ones you should not forget
Injury to structures near the injection site and embolic complications are rare but serious, which is why placement depth and the volume placed at each pass matter. General anaesthetic risks apply. And the risk that is easiest to overlook is not surgical at all: a new breast lump after this operation must be assessed on its own merits rather than assumed to be a consequence of the surgery.
Seek care rather than waiting
- Rapidly increasing swelling, a tense painful area, or bleeding that will not stop with pressure.
- Spreading redness, warmth, fever above 38 °C, or discharge from an incision.
- Any new lump, skin change or nipple discharge — report it for assessment rather than assuming it is from the surgery.
The screening consequences are set out in full under calcification and mammography, and what can be done about irregularity is covered in one session or two.
Frequently asked questions
What is fat necrosis and does it need treatment?
It is transferred fat that has not established a blood supply, so the cells die and are replaced by oil and scar tissue. It can present as an oil cyst or a firm area. Some resolve on their own, some are drained with a needle, and occasionally removal is needed. It is a recognised consequence of the operation rather than a technical error.
How common is infection?
Uncommon, and usually treatable with antibiotics; occasionally drainage is needed. The risk is higher where there has been previous surgery in the area. A breast that becomes red, hot, painful and swollen, particularly with fever, needs prompt assessment rather than waiting for a scheduled review.
Will the two sides look the same?
Most breasts are asymmetric before surgery, and the operation narrows the difference rather than removing it. Unevenness that is obvious at two weeks often improves by three months as swelling settles. Persistent asymmetry at six months can sometimes be refined with a small additional procedure.
Risks & Limitations
- A proportion of the transferred fat is always reabsorbed. How much cannot be predicted, and a second session is often needed.
- The size increase is usually moderate rather than large; under-correction is the commonest cause of dissatisfaction.
- Fat transfer does not lift the breast and cannot correct significant ptosis. A mastopexy is a different operation.
- Calcification, oil cysts and fat necrosis after fat transfer can make later mammography harder to interpret and may lead to extra imaging or a biopsy.
- Irregularity, palpable lumps or asymmetry within the breast.
- Infection, bleeding, or a collection of blood that may need drainage or antibiotics.
- Bruising, soreness, numbness and contour irregularity at the donor site; permanent donor and recipient scars.
- Rare but serious risks include injury to structures near the injection site and embolic complications; general risks of anaesthesia apply.
When to Seek Care
- Difficulty breathing or shortness of breath — seek emergency care immediately.
- Rapidly increasing swelling, or a tense, painful, tight area in either breast.
- Fever above 38 °C, spreading redness, warmth, or discharge from an incision.
- Bleeding that does not stop with gentle pressure.
- Any new breast lump, skin change or nipple discharge — report it for assessment rather than assuming it is from the surgery.
References & Further Reading
- American Society of Plastic Surgeons (ASPS) — fat grafting and breast surgery guidance
- International Society of Aesthetic Plastic Surgery (ISAPS)
- American Cancer Society — breast screening and mammography information
- National Institute for Health and Care Excellence (NICE, UK) — relevant guidance
- Cochrane Library — systematic reviews in breast and plastic surgery
This page is patient education, not medical advice, and it does not cite individual studies. Discuss your own case with a qualified clinician. To arrange an assessment at Chongqing West District Hospital, see Contact & Consultation.