What is lipoma?

A lipoma is a benign, or non-dangerous, new growth of fatty tissue. They can occur anywhere in the body, and can often be found growing underneath the skin. They grow very slowly and very rarely turn into a tumour that is cancerous.

It is the most common soft tissue growth of adulthood and is most commonly found in patients aged between 40 and 60 years old, but can also be found in children. It is more common in men, though women are also able to get lipomas. In some instances, there is a familial tendency for growth of lipomas.

There are different names given to lipomas, depending on where it originated from and what cells make up the new growth. They can grow to many different shapes and sizes.

Statistics

Lipomas have been shown to occur in all age groups, but most commonly from the age of 40 onwards. It has been shown to be more common for men to be affected, but many women can still be affected. There are some families where people are genetically more prone to get lipomas, and they usually have more than one lipoma present around their bodies.

Risk factors

Lipomas usually occur in people without any obvious predisposing causes. In some instances, there is a tendency of getting lipomas in the family which are thought to be due to a genetic cause. With some people, if they suffer from a certain syndrome or illness (such as Gardner’s syndrome or Madelung’s disease), it is part of the syndrome that numerous lipomas can occur.

Progression

Lipomas are common and are normally benign – they do not grow to become cancers. Therefore, there is no medical reason for removal apart from cosmetic reasons or if there is discomfort from pressure. They are slow growing and removal generally stops its growth.

In very rare circumstances, lipomas are cancerous or become cancerous. They are what is known as liposarcomas, a soft tissue tumour. Liposarcomas are the most common sarcomas of adulthood and appear in those in their forties to sixties; they are uncommon in children. They are usually found in the deep tissue and if not completely removed, tend to recur at the same site where it originated.

Symptoms

Lipomas are generally:

  • Soft and fluctuant;
  • Well defined, shaped like a lobule;
  • Feel rubbery;
  • May be one or many;
  • Painless;
  • Most common on limbs (especially arms) and trunk of the body;
  • Can occur at any site.

Lipomas tend to only be a problem if you are aware of its presence and believe it to be cosmetically a problem. Sometimes, they can grow in places that cause pressure on structures underneath the skin or causes the skin to be tethered and can be irritating.

Clinical examination

The doctor will want to examine the lipoma and you in general.

At the lipoma site

The doctor will look at the lipoma for its size and shape. They will also need to touch the area to feel for the consistency and whether or not it is causing pain or affecting other structures such as nerves or blood vessels.

In general

The doctor then may want to check for other possible areas of lipoma growth, and to make sure that it is a lipoma and not another cause. This may involve inspecting and examining your lymph nodes and other parts of the body. Over time, your doctor will want to monitor the lipoma and will measure its growth, as well as seeing if any other lipomas start to grow.

How is it diagnosed?

Lipomas are diagnosed usually by its characteristic shape, location and feel and history of a slow growing, painless lump that is under the skin. There is usually no need for further investigations if it fits the criteria for a lipoma and the doctor will normally recommend removal if you want it. Sometimes, if the doctor is unsure of the diagnosis or if it is an area with other important structures (such as blood vessels or nerves), then further imaging such as ultrasound of the lesion, X-rays or CT scans may be ordered. However this is used only rarely.

Prognosis

Very good outcomes, there is normally no recurrence if the lipoma is completely removed.

Treatment

Treatment can be either non-surgical or surgical.

Non-surgical treatments

Steroid injection

This involves injecting the area with a local anaesthetic and steroid injection to cause the lipoma to stop growing and shrink in size. There may be a need for multiple injections into the site to shrink the lipoma altogether. Steroid injections may not be useful for already large growths. There is a small risk of the skin being damaged, and not healing as well as it normally would. It is more effective for smaller lipomas in areas where it can be hard to access surgically.

Liposuction

Liposuction can be used in small or large lipoma growths where avoidance of scars is necessary. This can be done in a GP setting or through a surgery. Liposuction involves removing the fat with a large gauge syringe and local anaesthesia. Complete removal of all of the growth is very had to achieve, therefore the lipoma has a chance of growing back.

Surgical treatment

Surgical removal of a lipoma can occur at a GP practice, or your GP may want to refer you on to a surgical specialist. Surgery involves:

  1. Marking the area on the body;
  2. Injecting local anaesthetic;
  3. Making an incision appropriate for the size and shape of the lipoma;
  4. Using a gloved finger or blunt scissors to free the lipoma from the surrounding tissue and removing it;
  5. Closing up the incision with stitches and a dressing.

Surgical removal is seen as the procedure that allows for complete removal of the lipoma, and is very good at preventing regrowth.

Some complications include bleeding, formation of a bruise and infection at the site. However, your doctor will take steps to prevent this from happening. You must consult with your doctor as to what would be the best option for your circumstance.

References

  1. Salam GA. Lipoma excision. Am Fam Physician. 2002;65(5):901-4. [Full text]
  2. Koh HK, Bhawan J. Tumors of the skin. In: Moschella SL, Hurley HJ (eds). Dermatology (3rd edition). Philadelphia: Saunders; 1992:1721-808.
  3. Zuber TJ. Skin biopsy, excision, and repair techniques. In: Soft tissue surgery for the family physician [online]. American Academy of Family Physicians; 1998 (cited December 2007). Available from: [URL]
  4. Murtagh J. General Practice (3rd edition). Sydney: McGraw Hill; 2003.
  5. Kumar V, Abbas AK, Fausto N. Robbins and Cotran Pathologic Basis of Disease (7th edition). Philadelphia: Elsevier Saunders; 2004.
  6. Longmore M, Wilkinson IB, Rajagopolan S. Oxford Handbook of Clinical Medicine (6th edition). Oxford: Oxford University Press; 2004.
  7. Burkitt HG, Quick CRG. Essential Surgery (3rd edition). London: Churchill Livingstone; 2002.