Lipoma: causes, symptoms, treatment, prognosis
A lipoma is a lump under the skin, which is often troubling at first. Very often, however, there is a harmless cause behind it: A lipoma is a harmless new formation from fatty tissue. Lipomas do not necessarily have to be treated. But sometimes they hurt, become very large or visually disturb. Then a doctor can remove the lipoma. Read more about causes and therapies of lipoma.
A lipoma is a benign tumour of the fatty tissue, which usually does not cause any symptoms. It is therefore also called a fat tumour. The lipoma belongs to the soft tissue tumours. It consists of fatty tissue cells enclosed by a capsule of connective tissue.
As a rule, a lipoma is harmless, only rarely does this benign soft tissue tumour develop into a malignant tumour. Lipomas occur mainly in people over 30 years of age, less frequently in children. Men get these lumps under the skin somewhat more often than women.
Lipomas are usually located directly under the skin (subcutaneously) and can therefore be felt from the outside as round or oval nodes. More rarely, a lipoma can also grow in the musculature or in the area of the lumbar spine and sacrum. If a lipoma occurs on the head, it can also be a so-called subfascial lipoma. Subfascial means that it lies under a layer of connective tissue (fascia) that envelops a muscle. The subfascial lipoma on the head often grows at the transition from the forehead to the hair. Other places where subfascial lipomas often occur are the neck and the area of the shoulder blade.
Lipoma is very common, mainly on the arms and legs, the shoulders and neck as well as on the abdomen and flanks. Sometimes many lipomas occur simultaneously. Doctors then speak of a lipomatosis. Lipomas also occur more frequently in the context of the hereditary disease neurofibromatosis.
A lipoma grows slowly and usually only grows a few centimeters in size. However, rarely a lipoma can reach a diameter of more than ten centimetres (giant lipoma). A special form is the angiolipoma. This lipoma contains blood vessels that are usually blocked (thrombosed). The angiolipoma often causes pain. Young men are particularly affected. In more than half of the cases several angiolipomas occur simultaneously.
Another special form is the spindle cell lipoma, which occurs mainly in men between 45 and 60 years of age and is usually located on the back, neck or shoulder. The spindle cell lipoma usually causes no symptoms.
In most cases a lipoma does not cause any symptoms. Affected people often only notice a lump under the skin, which feels firm and rubbery and can be moved easily. Sometimes it causes pain when the lipoma is pressed. Depending on the location of the lipoma, pain can also occur when it is pressed or stretched during movements. Angiolipomas can be painful even without external influences.
Lipoma: causes and risk factors
It is not yet known why the lumps develop under the skin. It is possible that a genetic predisposition promotes the growth of a lipoma. However, this has not yet been clearly proven to be the cause of individually occurring lipomas.
The causes of lipomatosis, in which many lipomas occur simultaneously, are also not yet fully understood. Lipomatosis frequently occurs in patients who also suffer from metabolic disorders such as diabetes mellitus or excessive uric acid levels (hyperuricemia). However, it is not clear whether they are actually the cause of lipoma. It is also discussed whether too high blood lipid values (hyperlipidemia) can lead to lipomas.
There is a hereditary disease in which lipomas sometimes occur more frequently: neurofibromatosis. In addition to so-called neurofibromas, which give the disease its name, many lipomas also grow. Depending on the type of disease, they are mainly found on the body or on the arms and legs.
Lipoma: examinations and diagnosis
Anyone who notices lumps under the skin should always consult a doctor to rule out a malignant tumour. The doctor palpates the bump under the skin. He pays particular attention to whether it can be moved easily and is well separated from the remaining tissue. This is followed by an ultrasound and/or X-ray examination. In this way the doctor can often already distinguish the lipoma from cysts and other new formations (e.g. fibroma). It is also possible to see exactly how large the lump under the skin is. This is important because a lipoma is often larger than it can be felt through the skin.
If it is still not possible to determine with certainty after these examinations whether the bulge under the skin is actually a lipoma, a tissue sample is taken and examined under the microscope for fine tissue.
A lipoma can also develop in the female breast. In this case the doctor usually removes the lump under the skin to rule out the possibility of a liposarcoma. This is a malignant soft tissue tumor.
With a lipoma, therapy is not necessarily required. If it visually disturbs the affected person, hurts or is very large, the doctor can remove the lipoma. There are different possibilities for this, depending on the size of the lipoma and the location of the lipoma.
The lipoma and its connective tissue capsule can be completely removed by surgery. Lipomas that lie directly under the skin can be cut out particularly easily: A surgeon cuts into the skin above the lipoma and presses it out. The patient usually receives a local anaesthetic for this purpose. In the case of very large or numerous lipomas, a general anaesthetic may be necessary. A subfascial or muscular lipoma is somewhat more complex to remove, as it must first be exposed under the connective tissue or muscle. Nevertheless, a local anaesthetic is usually sufficient here as well. The surgeon then sutures the wound and applies a pressure dressing. Usually a scar remains after that. In the case of lipomatosis, the doctor can often remove several lipomas without the need for a second operation.
Anyone who wants to have a lipoma removed should be aware that even a minor operation can lead to complications. Bleeding may occur, the wound may become infected or heal poorly. If a general anaesthetic is necessary, there are also risks involved. Normally, however, complications rarely occur.
A more recent way of removing a lipoma is liposuction (liposuction). This means that the lipoma is not cut out but suctioned off. The advantage of this procedure is that less scar tissue is created than with surgery. However, it is not always possible to completely aspirate the lipoma together with its connective tissue capsule. Then the lipoma can continue to grow. For this reason, surgical removal is still usually the preferred therapy. Discuss with your doctor which procedure is best for you.
Lipoma: course of disease and prognosis
The lipoma has a good prognosis. There is only a very low risk that a malignant tumour will develop from the benign lipoma. A treatment is usually not necessary. Anyone who is bothered by the lump under the skin can have it removed by a doctor. However, a new lipoma can always form.