Lipoma

A lipoma is a benign (non-cancerous) growth of fat cells that forms a soft, rounded lump under the skin. Lipomas are among the most common soft tissue lumps in adults and can occur almost anywhere, most often on the trunk, shoulders, neck, arms and thighs. They typically feel soft or rubbery, move easily under the fingers, and grow very slowly over years. Most are small, but some can reach several centimetres in size.

Lipomas are usually painless, although they may cause discomfort if they press on a nerve or lie in an area that is rubbed by clothing or a belt. Some people have several lipomas, and there is sometimes a family tendency. The exact cause is not known. Lipomas do not turn into cancer, but not every fatty lump is a lipoma, which is why new or changing lumps should be examined.

Many lipomas can simply be left alone once the diagnosis is clear. Removal is considered when a lipoma is:

• Growing or has changed in character
• Painful, tender or uncomfortable, including catching on clothing
• Located where it interferes with movement or function
• A cosmetic concern
• Uncertain in diagnosis, particularly if it is large, deep, firm or fast-growing

Your surgeon will examine the lump and, where appropriate, arrange an ultrasound or MRI scan to confirm that it is a simple lipoma and to assess its depth and relationship to surrounding structures. Lumps that are deep, larger than about five centimetres, or growing rapidly may need further assessment before surgery to exclude other fatty tumours, and in some cases a biopsy is recommended first.

Lipoma removal (excision) is a day-surgery procedure. Small superficial lipomas can often be removed under local anaesthetic, with the area numbed while you remain awake. Larger or deeper lipomas, those in sensitive areas, or several lipomas removed at once are usually treated under general anaesthesia.

An incision is made in the skin over the lump, following natural skin lines where possible to minimise the visible scar. The lipoma is separated from the surrounding tissue and removed whole, and the wound is closed with stitches, which may be dissolving or may need removal after a week or two. The procedure typically takes between fifteen and forty-five minutes depending on the size and position of the lipoma, and you can go home the same day.

Every lipoma that is removed is sent to a pathology laboratory, where it is examined under a microscope to confirm the diagnosis. This is a routine step and is done even when the lump looks entirely typical, because it provides certainty that the lump was a simple lipoma and nothing more.

Very occasionally, a lump that was thought to be a lipoma proves to be a different type of fatty tumour. If this happens, your surgeon will discuss the result with you, arrange any further tests that are needed and, where appropriate, refer the case for multidisciplinary review. Results are usually available within one to two weeks and are discussed with you at your follow-up appointment or by telephone.

Recovery after lipoma removal is usually straightforward. Some bruising, swelling and tenderness around the wound are expected for a week or so and settle with simple pain relief. Keep the dressing clean and dry as advised, and avoid soaking the wound until it has healed.

Most people return to work and normal daily activities within a day or two after a local anaesthetic procedure, or within a few days after a general anaesthetic. Heavy lifting or strenuous exercise involving the area should be avoided for about two weeks to allow the wound to heal and reduce the risk of bleeding under the skin. A small scar is unavoidable and fades over several months. Lipomas seldom return once completely removed, but new lipomas can develop elsewhere. Contact the practice if you notice increasing redness, discharge, swelling or pain at the wound.