A lipoma is a benign lump made up of fat cells; it is noticed under the skin as a soft swelling that moves slightly when pressed, grows slowly and is usually painless [1][4]. It is harmless and usually needs no treatment, but it is still recommended that any lump you notice is shown to a doctor [1]. A lump that is growing, painful, hard and does not move, larger than 5 cm or deep-seated should be assessed by examination and imaging rather than assumed to be a lipoma [1][5].
What is a lipoma? Is it the same as a cyst?
A lipoma is a benign (non-cancerous) lump made up of fat cells, and it usually sits in the fatty layer under the skin [1][4]. It is the most common soft tissue tumour in adults [2] and by far the most common cause of a soft tissue lump on the arms, legs and trunk [5].
In everyday language the same words ("fatty lump"; in Turkish, "yağ bezesi") are used for both a lipoma and a skin cyst; the two are different. A skin cyst is a round lump just underneath the skin that often contains fluid or pus; it sometimes has a small, dark spot in the middle and can get red and sore if it becomes infected [3]. A cyst that develops in the top layer of the skin is called an epidermoid cyst or a "sebaceous cyst" [3]. A lipoma contains fat tissue [1][2]. An ultrasound, CT or MRI scan is sometimes needed to distinguish a lipoma from cysts [4]. This article is about lipoma.
How does it feel and where does it appear?
A lipoma feels soft, squishy or rubbery; it moves slightly under the skin when pressed, grows slowly and is usually painless [1][2][4]. Its size ranges from that of a pea to a few centimetres [1]; it usually stays under 10 cm [4].
It is most often found on the shoulders, chest, arms, back, buttocks and thighs [1][2]. One person can have more than one lipoma [2]. Less commonly it lies in the deeper tissue of the thigh, shoulder or calf; these take longer to notice and can be quite large by the time they are noticed [2].
Most lipomas are painless; they may be painful if they press on nerves or neighbouring structures or if they contain many blood vessels [4].
Lipomas can also occur on the head and neck [7]; lumps on the head, face and neck are assessed by the relevant specialty, and lumps on the arms, legs and trunk by orthopaedics and traumatology.
Why does it form, and who gets it?
The exact cause of lipomas is not well understood; most arise spontaneously without a clear cause [4]. Age, gender, hormone imbalances and trauma to the area are listed among the factors that may increase the likelihood [4]. Some research suggests that the risk may be higher in people who have a family member with lipomas [4]; some subtypes may be inherited [2]. There is no proven connection with any particular occupation or exposure [2]. Although they can be found at any age, they usually appear between the ages of 40 and 60 [2][7].
Is a lipoma dangerous?
A lipoma is harmless [1]. It does not typically change after it forms and has very little potential for becoming cancerous [2].
The reason for the warning features is that other tumours also arise from fat tissue. A liposarcoma is a cancer; it typically grows quickly and is not as moveable as a lipoma [2]. An atypical lipomatous tumour is a fatty tumour that can increase in size over time but does not generally spread to other parts of the body [2][5]; it is many times less common than a lipoma and tends to be larger, deep-seated and in the leg [5]. It is a very rare possibility that a lump is a liposarcoma; to rule this out, a lump that is growing may need further investigation such as a biopsy [4].
How is it diagnosed? Examination, ultrasound and MRI
The doctor asks how long the lump has been there and about symptoms such as pain, and checks its size, consistency and mobility [2]. A doctor can usually tell from the examination that the lump is a lipoma and asks for a scan if there is any doubt [1].
Ultrasound is an effective initial triage tool for soft tissue lumps, and most lumps are diagnosed in this way as benign lipomas [5]. Its result depends heavily on the person performing it; if the diagnosis remains uncertain, an MRI of the area is performed [5]. MRI shows that the lump is made up of fat tissue; the diagnosis is often made on MRI alone and a biopsy is not required [2].
MRI is not always enough to tell a large, deep lipoma from an atypical lipomatous tumour; the defining test is a genetic test (MDM2) on tissue obtained by needle biopsy [5].
Does it go away with creams or at home?
A lipoma usually needs no treatment and can simply be left alone [1][6]. However, it does not typically change after it forms [2]; surgery is the only reliable way to remove benign lumps of this kind [6]. None of the sources used for this article lists a cream, ointment, medicine or any home method as a treatment for lipoma [1][2][4][6].
Do not squeeze the lump: if a skin cyst is squeezed and bursts it could become infected, and if it is already infected the infection might spread [3]. Removing a lipoma is a surgical procedure performed by a doctor, and even in those conditions it carries risks such as bleeding, infection and nerve damage [6]; do not try to cut it out or drain it at home. If a lipoma is not treated, regular visits to the doctor are recommended to monitor any changes [2].
How is a lipoma removed? Surgery and other methods
There is no medical need to remove the vast majority of lipomas [4]. Surgery can be considered if the lump is growing, is causing symptoms because of where it is, is painful or is interfering with daily activities [1][2]; lipomas are also often removed for cosmetic reasons [4].
The operation is usually performed under a local anaesthetic and usually takes 15 to 25 minutes: the surgeon makes a straight cut over the lump, frees the lipoma from the tissues around it and removes it [6]. Lipomas smaller than 5 cm can be removed as an in-office procedure with local anaesthetic; those that are larger than 5 cm or deep usually require the operating room [2]. The removed tissue may be sent to a laboratory to check that it is a lipoma [1].
Non-surgical methods have also been described. A cortisone (steroid) injection shrinks the lipoma and rarely eliminates it altogether; it is best suited to lipomas less than 1 inch (about 2.5 cm) in diameter [7]. Liposuction can be used particularly in places where a large scar should be avoided, but complete removal of the lump is difficult to achieve with this method [7].
After the operation: recovery and recurrence
You can return to work the next day unless your work places a strain on the stitches [6]. The wound is checked in 2 to 7 days; the stitches are removed after 7 to 21 days, depending on the part of the body [7]. Most surgeons recommend light activities for 2 to 4 weeks after surgery [2]. Possible problems are bleeding, wound infection, wound breakdown, a numb patch of skin, pain and scarring [6].
A lipoma is almost always cured by simple excision; it is unusual for it to grow back [2]. Atypical lipomatous tumours grow back more frequently [2][5]; for this reason, a lump that grows back in the same place after removal needs to be assessed.
When not to wait
Not every soft lump is a lipoma. A soft tissue sarcoma also most commonly presents as a painless, enlarging lump; the absence of pain does not show that a lump is harmless [5]. Show any lump you newly notice to a doctor [1].
The following features do not mean that the lump is malignant: growth, a size of more than 5 cm, a deep site and pain are also found in far more common benign lumps such as lipomas and cysts, and a small proportion of the patients referred on these criteria prove to have a sarcoma [5]. Even so, do not wait if one of them is present; the distinction is made by examination and imaging [1][2][4][5]:
- A lump that is growing, especially one that is growing quickly
- A lump that is painful, or red or hot
- A lump that is hard and does not move
- A lump larger than 5 cm
- A deep-seated lump
- A lump with bleeding or a sore in the skin over it
- A lump that grows back in the same place after it has been removed
Frequently asked questions
- Is there a cream that dissolves a lipoma?
- None of the sources used for this article lists a cream or a home method as a treatment [1][2][4]. Surgery is the only reliable way to remove benign lumps of this kind; the lump can also simply be left alone [6].
- Can a lipoma turn into cancer?
- A lipoma has very little potential for becoming cancerous [2]. However, not every fatty lump is a lipoma; a lump that is growing may need further investigation such as a biopsy to rule out liposarcoma, which is a very rare possibility [4].
- How long does lipoma surgery take?
- The operation is usually performed under a local anaesthetic and usually takes 15 to 25 minutes [6]. Lipomas that are larger than 5 cm or deep usually require the operating room [2].
This article is a general summary; diagnosis and treatment decisions are made by the doctor who examines you.
Sources
- Lipoma. NHS (nhs.uk), 2023. nhs.uk
- Lipoma. American Academy of Orthopaedic Surgeons (OrthoInfo), n.d.. orthoinfo.org
- Skin cyst. NHS (nhs.uk), 2023. nhs.uk
- Lipoma. British Association of Dermatologists (BAD), 2024. skinhealthinfo.org.uk
- UK guidelines for the management of soft tissue sarcomas. British Journal of Cancer (Hayes AJ, et al.), 2024. pubmed.ncbi.nlm.nih.gov
- Removing benign skin lesions. Healthdirect Australia, 2026. healthdirect.gov.au
- Lipoma excision. American Family Physician (Salam GA), 2002. pubmed.ncbi.nlm.nih.gov
This article is general information and does not replace an examination or imaging. If you have symptoms, see a doctor.