Lipomas are the most common cause for a lump under the skin. They may be single although some people make multiple lipomas particularly on their arms although they may occur anywhere in the body. Frequently they are quite small measuring up to an inch (2cm) in size although they can grow to be very large. Typically they cause few symptoms but they can be quite tender even painful. A condition where there are lots of painful lipomas is called Dercum’s disease.
Malignant tumours of fat, called liposarcomas, are very rare. Benign lipomas do not become cancerous (i.e.do not turn into liposarcomas).
If a lump is confidently diagnosed as a lipoma there is no need for it to be removed if it is not painful or growing. If it is causing symptoms or there is doubt about the diagnosis then surgical removal is usually advisable.
The operation is usually carried out under local anaesthetic (injection to make the skin numb). Larger lipomas or those lying deeper, such as in muscle, may require a general anaesthetic (asleep). It is usually classified as an outpatient or daycase procedure. You are usually only in the hospital for a short period before and after the procedure. With larger lipomas a surgical drain and an overnight stay in hospital may be necessary.
Usually a cut is made over the lump which is then removed. If the lump is in the skin then it is usually excised by removing a diamond shaped piece of skin with the cyst in the centre. The diamond shape is then closed with stitches to leave a straight line. Stitches may be absorbable (dissolving) or may need to be removed. On the face usually stitches that need to be removed are used.
It is usual practice for all bits of skin or lumps that are removed to be sent to the histology laboratory for analysis to check they are benign. In some instances the diagnosis may be so clear that this is not necessary.
With all surgery there is the possibility of complications. The main complications with removal of lipomas are:
Bleeding: bleeding following surgery occasionally results in the need to re-operate to stop bleeding or to remove a build up of blood under the skin (haematoma).
Infection: there is always a small risk of an infection with surgery. Usually these will settle with antibiotics. Rarely they can be serious.
Wound break down and slow healing: if the wound opens up, usually due to infection, then healing can be slow afterwards.
Damage to nerves: at certain sites, particularly on the face, there are small but important nerves running under the skin. These can be damaged during surgery. It is more likely where there are deeper lumps.
Poor scarring: scarring depends more on how an individual heals than on how the operation is carried out. Some people make great scars that may be difficult to see. Other people’s scars may stretch or turn hypertrophic and keloid. Hypertrophic and keloid scars tend to be lumpy, red, itchy even painful and may take a long time to settle.
Recurrence: lipomas that have been removed may sometimes grow back.