Fat graft lumps: oil cysts, fat necrosis, calcification and what can be done

What they are

What fat graft lumps can be

"Lump" covers several different things after fat grafting. Some are simply an uneven distribution of surviving fat: a ridge, a bump at the end of an injection track, or an area that took better than its neighbour. These feel like soft fat and do not usually change much once the graft has settled.

Others are a reaction to fat that did not survive. Fat necrosis forms a firm, rubbery nodule; an oil cyst is a pocket of liquid oil walled off by scar tissue; over time the wall of a cyst or necrotic area can calcify and feel hard. A granuloma, sometimes called a lipogranuloma, is an inflammatory reaction to free oil, fibrous material or blood in the graft.

Not every lump in a grafted face comes from the graft. Hyaluronic acid filler, other fillers such as calcium hydroxylapatite or poly-L-lactic acid, a lipoma, a skin cyst or a swollen gland can all appear in the same areas, which is why the history and examination matter.

How they form

Why fat graft lumps form

Grafted fat has no blood supply of its own at first. Cells at the edge of each parcel survive by drawing oxygen from surrounding tissue while new vessels grow in; cells at the centre may die. When fat is placed in larger parcels, the centre is too far from a blood supply and fat necrosis follows. That is why surgeons inject tiny amounts per pass in a fanning pattern.

A review of facial fat grafting complications notes that large areas of necrosis, more than about 10 mm across, can turn into oil cysts, and that the inflammatory response to oil cysts can lead to calcification. Free oil from fat cells damaged during harvesting is taken up by immune cells, which can cause inflammation, granulomas and irregularity.

Placement matters too. Superficial injection in thin skin, particularly around the eyes and in the tear trough, makes any unevenness easier to see and feel. A 2026 review of fat necrosis after facial grafting also identified cryopreserved (frozen and stored) fat and repeat grafting sessions as common risk factors.

Oil cysts and calcification

Oil cysts and calcified fat graft lumps

An oil cyst is a pocket of oil from dead fat cells, surrounded by a fibrous wall. In a study of oil cysts removed two to six years after cosmetic fat grafting to the breast, the walls showed ongoing inflammation and eggshell-like calcification, and cysts with a longer history had more calcification. The authors concluded that once fat necrosis has formed an oil cyst, chronic inflammation can persist and calcification can keep progressing for years.

Oil cysts are reported more often after large-volume grafting of the breast or buttocks than in the face, where volumes are small. In the face they are usually small, smooth and mobile. According to the same review, oil cysts can typically be treated with needle drainage and only rarely need surgical excision; a calcified lump does not drain and, if it is troublesome, is removed surgically.

How common

How often do lumps occur after facial fat grafting?

Estimates vary because studies define and report complications differently. A systematic review of 18 studies and 3,073 patients having facial fat transfer found an overall complication rate of about 6%, with fat necrosis or oil cysts in about 2% and irregular fat distribution in about 2%. A separate review cites contour irregularity rates of 0.54% to 2.9% across recent meta-analyses.

Looking only at what went wrong, a 2022 review of 298 reported adverse events after facial fat grafting found irregularities made up about 19% and fat necrosis about 7%. The authors stressed that the true complication rate is unknown because of under-reporting.

Where lumps appear also follows a pattern. In the 2026 fat necrosis review, the area around the eyes was affected more often than any other, often after injections into the forehead or between the brows, and nodules typically presented as firm lumps that often did not hurt, weeks to months after the procedure.

Diagnosis

How imaging tells fat graft lumps apart

Diagnosis starts with the history and examination: when the lump appeared, whether it has changed, whether it hurts, how it feels and how it moves. In the 2026 review of facial fat necrosis, diagnosis was largely clinical, with imaging and tissue sampling used selectively.

High-frequency ultrasound is a practical first scan in the clinic. A 2026 review of filler imaging describes material-specific patterns: HA filler tends to appear as dark, fluid-like pockets, while grafted fat appears as soft-tissue nodules that may show changes of fat necrosis. Ultrasound can also show whether a lump is solid or cystic, how deep it sits, and, with Doppler, whether it is inflamed.

CT or MRI is sometimes used to show calcification, oil cysts or deeper fat. In breast imaging, the appearance of fat necrosis ranges from typically benign to one that can mimic cancer, which is why a lump with unusual features, or one that keeps growing, may need specialist review or a biopsy rather than assumptions.

Warning signs

When a lump needs prompt attention

See your surgeon or a doctor promptly if a lump becomes red, hot, increasingly painful or swollen, discharges, or comes with a fever. Infection and active inflammation are treated differently from a quiet nodule, and some treatments, such as steroid injection, are not given into an infected area.

A lump that keeps growing, feels fixed or hard, or appears long after grafting without explanation should also be checked rather than assumed to be graft. Any change in vision, eye pain, or facial or limb weakness after a facial injection or graft is an emergency: go to an emergency department at once.

Options

Treatment options for fat graft lumps

Small lumps that do not hurt and are not changing can often be watched. The 2026 review found observation appropriate for small lesions without symptoms, and many lumps soften as swelling and inflammation settle over the first months.

For inflamed fat necrosis nodules and lipogranulomas, corticosteroid, given as tablets or as small injections into the nodule, was the treatment reported as successful in the largest number of cases. Early granulomas have also been treated with needle drainage, warm compresses, massage, and injections of triamcinolone or 5-fluorouracil. These are medicines given by a doctor after assessment; steroid injected too much or too shallow can thin the skin or leave a dent, so doses are kept small.

Oil cysts can usually be drained with a needle. Persistent, calcified or troublesome lumps are removed by excision, and areas of uneven excess graft may be smoothed by microliposuction; both are surgery, done by a plastic or oculoplastic surgeon. Energy-based treatment such as Time Freeze Laser LCLR® is aimed at diffuse excess graft near the surface, not at a discrete hard lump or cyst. Hyaluronidase helps only if the lump is HA filler.

Who to see

Your surgeon, a second opinion or a specialist

The surgeon who did the graft knows what was placed, where and how much, and is usually the first person to see, particularly in the first months. If that is not possible, or you are unsure what the lump is, a doctor who can examine and scan the area can give a second opinion.

Lumps on or near the eyelids are usually better handled by an oculoplastic surgeon, and surgical removal elsewhere on the face by a plastic surgeon. A lump with unusual features may need a dermatologist, imaging or a biopsy to make a diagnosis.

At SkinRev Lab

Having a lump assessed by Dr Sin Yong

At SkinRev Lab, licensed by the Ministry of Health as SkinRev Clinic, your consultation is with Dr Sin Yong. He asks when and where you were grafted, whether filler was used, and how the lump has behaved, examines it, and uses ultrasound where it helps to tell graft, cyst and filler apart. His approach is to identify what is there before treating, to treat only what is causing the problem, and to include no treatment as an option.

Depending on what he finds, he may advise watching it, dissolving a lump that turns out to be HA filler, a doctor-led measure where the evidence supports it, or referral to a plastic or oculoplastic surgeon, or for imaging, when removal or a diagnosis is needed. He does not perform fat grafting, liposuction or excision surgery. Treatment is priced at consultation.

Consultations are at SkinRev Lab, #B1-28 CityLink Mall, 1 Raffles Link, linked underground to City Hall and Esplanade MRT, open daily 11am to 8pm (WhatsApp +65 8266 9585), and at IN Eternity Clinic, 9 Scotts Road, #12-01 Pacific Plaza, beside Orchard MRT (WhatsApp SkinRev Lab on +65 8266 9585 or IN Eternity Clinic on +65 8815 3008).

Sources

References & sources

1. Jerliu A, Watters A, Harrison L, et al. Fat necrosis after facial autologous fat grafting: a systematic review of reported complications and management strategies. Aesthetic Plast Surg. 2026;50(17):7248-7259.
2. Brown K, McCoskey M, Nakra T. Complications of facial autologous fat grafting. Plast Aesthet Res. 2024;11:7.
3. Mineda K, Kuno S, Kato H, et al. Chronic inflammation and progressive calcification as a result of fat necrosis: the worst outcome in fat grafting. Plast Reconstr Surg. 2014;133(5):1064-1072.
4. Groen JW, Krastev TK, Hommes J, et al. Autologous fat transfer for facial rejuvenation: a systematic review on technique, efficacy, and satisfaction. Plast Reconstr Surg Glob Open. 2017;5(12):e1606.
5. Schiraldi L, Sapino G, Meuli J, et al. Facial fat grafting (FFG): worth the risk? A systematic review of complications and critical appraisal. J Clin Med. 2022;11(16):4708.
6. Khorasanizadeh F, Momeni A, Daneshvar A, et al. Ultrasonographic evaluation of cosmetic fillers: patterns and frequent complications. A literature review. Clin Imaging. 2026;131:110708.
7. Taboada JL, Stephens TW, Krishnamurthy S, Brandt KR, Whitman GJ. The many faces of fat necrosis in the breast. AJR Am J Roentgenol. 2009;192(3):815-825.

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