Lipoma

A lipoma is a lump made of fat cells. It usually develops just beneath the skin, although lipomas can also form deeper inside the body. A lipoma is benign, meaning it is not cancer.

Most lipomas feel soft or rubbery and move slightly when pressed. They tend to grow slowly over months or years. Common locations include the shoulders, upper back, neck, arms, abdomen, buttocks, and thighs.

Lipomas are often painless and do not need treatment. They matter because any new lump should be identified correctly. Other conditions can resemble a lipoma, and a lump that is firm, fixed, deep, painful, or growing quickly may need imaging or a tissue sample.

A lipoma is different from a liposarcoma, which is a rare cancer of fatty tissue. An ordinary lipoma does not usually become a liposarcoma. However, it is not always possible to tell different types of lumps apart by touch alone.

Some people have one lipoma, while others develop several. Having multiple lipomas does not automatically mean that something serious is wrong.

A typical lipoma is a rounded or oval lump beneath the skin. It may be very small or grow to several centimetres across.

Common features include:

• A soft, doughy, or rubbery feel
• Slight movement under the skin when pressed
• Slow growth
• Little or no pain

A lipoma can sometimes be tender. Pain may occur if it presses on a nearby nerve, contains many blood vessels, or sits where clothing or movement repeatedly irritates it. A deep lipoma within or between muscles may feel firmer and may not move easily.

The skin over a lipoma usually looks normal. Redness, warmth, drainage, or a sudden increase in pain is not typical and may suggest inflammation, infection, or another cause.

Appearance and texture alone cannot confirm every lump. Features that deserve timely assessment include rapid growth, a size greater than about 5 centimetres, a deep position, firmness, fixation to nearby tissues, or unexplained pain. These features do not prove that a lump is cancerous, but they may lead to further testing.

The exact cause of most lipomas is unknown. They form when mature fat cells grow into a defined mass, often surrounded by a thin covering called a capsule.

Lipomas sometimes run in families. Familial multiple lipomatosis is an uncommon inherited condition in which a person develops multiple lipomas, often on the trunk and limbs. Other rare disorders can also involve multiple or painful fatty lumps.

Lipomas are most often noticed in adulthood, although they can occur at other ages. A previous minor injury is sometimes reported at the site, but it is not clear that injury causes a lipoma.

Body weight does not fully explain why lipomas form. People of any body size can develop them. A lipoma is a separate collection of fat cells, so losing weight usually does not make it disappear.

A healthcare professional can often recognise a superficial lipoma by examining and feeling it. They may ask how long the lump has been present, whether it has changed, and whether it causes pain or affects movement.

Imaging may be needed when the lump is large, deep, firm, painful, growing, or difficult to identify. It may also be used before surgery.

An ultrasound uses sound waves to show whether a lump is solid or filled with fluid and how it relates to nearby tissues. Magnetic resonance imaging, or MRI, provides more detailed images of deeper soft tissues. A CT scan may be used in some situations, particularly for a mass inside the chest, abdomen, or another deep area.

If the diagnosis remains uncertain, a biopsy may be recommended. During a biopsy, a small sample of tissue is removed and examined under a microscope. An entire small lump may instead be removed and sent for laboratory examination.

A simple fatty appearance on imaging may support the diagnosis, but suspicious or unusual masses need careful assessment. Referral to a specialist may occur before biopsy or removal when a soft-tissue cancer is a possibility. Planning the biopsy correctly can matter if further surgery is later needed.

A lipoma that has typical features, causes no problems, and has been assessed may only need monitoring. This means watching for changes rather than having regular tests in every case.

Removal may be considered if the lipoma:

• Is painful or tender
• Limits movement or presses on a nerve
• Continues to grow
• Is repeatedly irritated
• Causes significant concern about appearance
• Has an uncertain diagnosis

Surgical removal is the usual treatment. A small, superficial lipoma may be removed through a cut in the skin using local anaesthetic, which numbs the area. Larger or deeper lipomas may need a more involved operation and sometimes a general anaesthetic.

The surgeon usually removes the fatty lump and its capsule. The tissue may then be examined under a microscope to confirm what it is.

Possible effects of surgery include a scar, bruising, bleeding, infection, fluid collecting under the skin, numbness, or injury to nearby structures. The risks depend partly on the lipoma’s size and location. A lipoma can return if some of it remains, although complete surgical removal often prevents regrowth at that site.

Liposuction, which removes fat through a narrow tube, is occasionally used for selected lipomas. It may leave a smaller scar, but it can be harder to remove the entire capsule. This may increase the chance that the lump returns and may limit examination of an intact specimen.

Most lipomas do not cause complications. They may stay small and painless for many years.

A large or poorly positioned lipoma can press on nerves, muscles, blood vessels, or other structures. This may cause pain, tingling, weakness, restricted movement, or pressure symptoms. Deep lipomas can become quite large before they are noticed.

A visible lump may also affect comfort, clothing choices, or confidence. These concerns are valid reasons to discuss management, even when the lipoma is medically harmless.

Complications after removal are uncommon but can include infection, bleeding, scarring, altered sensation, or recurrence. Surgery near important nerves or blood vessels may carry additional risks.

The main concern during assessment is not a lipoma turning into cancer. Rather, it is making sure that a lump with unusual features is not a different type of growth.

There is no proven way to prevent an ordinary lipoma. Diet, exercise, massage, creams, and supplements have not been shown to stop one from forming.

Inherited tendencies to develop multiple lipomas cannot currently be prevented. If several close family members have multiple lumps, discussing the family pattern during a medical assessment may help guide diagnosis.

Maintaining a healthy weight can support general health, but it does not guarantee that lipomas will not develop. Weight loss should not be expected to remove an existing lipoma.

Many lipomas remain stable or grow very slowly over years. They usually do not affect general health, life expectancy, work, exercise, or everyday activities.

You may find it useful to remember where the lump is and whether it changes. Measuring it occasionally can be more reliable than checking it repeatedly by touch. Photographs may help when the lump is visible, provided they are stored in a way that protects your privacy.

Routine follow-up is not always needed after a typical lipoma has been assessed. Arrange another review if it becomes larger, harder, less movable, painful, or otherwise different. A new lump elsewhere should be assessed on its own features rather than assumed to be another lipoma.

After complete removal, the same lipoma often does not return. However, surgery cannot prevent a different lipoma from developing in another location. People with an inherited tendency may continue to develop new lumps over time.

Recovery after removal depends on the size, depth, and location of the lump. A small skin procedure may heal quickly, while surgery for a deep or large lipoma can require more time and limits on activity. The treating team can explain wound care and expected recovery for the procedure performed.

Arrange a routine medical appointment for a new lump, even if it feels soft and painless. This is especially important if you are not sure how long it has been present. Most lumps are not cancer, but examination is the safest way to decide whether testing is needed.

Seek a prompt appointment if a lump:

• Is growing quickly or clearly changing
• Feels firm, fixed, or deep
• Is larger than about 5 centimetres
• Causes persistent or increasing pain
• Returns after previous removal
• Causes numbness, weakness, or restricted movement

Redness, warmth, drainage, fever, or worsening tenderness may indicate infection or inflammation and should also be assessed promptly.

A suspected lipoma is rarely an emergency. Seek emergency care if a lump is associated with severe breathing difficulty, fainting, sudden major weakness, uncontrolled bleeding, or another serious new symptom. These are not typical features of a simple lipoma and need assessment for other causes.

Can a lipoma turn into cancer?

An ordinary lipoma does not usually turn into cancer. Liposarcoma is a separate type of tumour that can sometimes resemble a lipoma. A rapidly growing, firm, deep, painful, or unusually large lump may need imaging or biopsy to tell them apart.

Will losing weight make my lipoma go away?

Usually not. A lipoma is a defined growth of fat cells rather than ordinary body fat. It may become more noticeable after weight loss because the surrounding layer of fat becomes thinner.

Can I remove a lipoma at home?

No. Cutting, squeezing, puncturing, or injecting a lump at home can cause bleeding, infection, nerve injury, and scarring. It also prevents proper diagnosis. Removal should be performed in an appropriate medical setting.

Why does my lipoma hurt?

A lipoma may hurt if it presses on a nerve, contains many small blood vessels, or is irritated by movement or pressure. Pain can also mean that the lump has another cause, so a painful or newly tender lump should be assessed.

Do lipomas grow back after surgery?

A completely removed lipoma often does not return at that site. Regrowth can happen if part of the lump or its capsule remains. Developing another lipoma elsewhere is also possible, especially if you have multiple lipomas.

Do all lipomas need a scan or biopsy?

No. A small, superficial lump with typical features may be diagnosed by examination. Imaging or biopsy is more likely when a lump is deep, large, growing, painful, fixed, or otherwise uncertain.