Neurofibroma: what it is, symptoms, causes and treatment

A neurofibroma is a growth that develops from the cells around a nerve. The NHS describes neurofibromas as lumps on or just under the skin and as a typical feature of neurofibromatosis type 1 (NF1), a genetic condition in which tumours grow on the nerves and skin. NF1 is usually mild but, as the NHS says, some people have symptoms that cause problems.

Nerve Tumours UK, the UK charity for people affected by neurofibromatosis, describes skin neurofibromas as soft, small lumps that appear on the skin and are very common in people with NF1. It says most are not dangerous but can be tricky to live with.

The sources read for this page describe neurofibromas almost entirely in the context of NF1. They do not explain how often a single neurofibroma occurs without NF1, so if you have found one lump and no other features, your GP is the right person to assess it.

Many neurofibromas need no treatment. The NHS says that if NF1 symptoms are not causing any problems, your doctor may suggest waiting to see if any problems develop before starting treatment. When treatment is wanted, Nerve Tumours UK says the choice depends on the lump and your doctor will help choose, and that all of the treatments take time, with healing taking a few weeks.

Nerve Tumours UK says some neurofibromas may grow very large, become twisted or red, or get infected, and in those cases you may need to see a doctor, take antibiotics or have surgery to remove the lump. It adds that most people with NF1 are not complex cases and can be treated by doctors in plastic surgery units across England, Scotland, Wales and Northern Ireland, while two specialist clinics for complex NF1 are based in London and Manchester.

For deeper tumours, the NHS lists treatments for NF1 including medicine to stop tumours growing, surgery to remove tumours that are at risk of causing problems and radiotherapy for small tumours or pieces left after surgery. NICE says selumetinib is available on the NHS for plexiform neurofibromas that are causing symptoms and cannot be removed by surgery in people aged 3 to 17 with NF1.

Most skin neurofibromas show as soft lumps that can be seen, especially on the face, arms or body. The NHS says they can be painful or itchy, and Nerve Tumours UK adds that they can be a source of embarrassment or frustration and can attract unwanted attention.

Neurofibromas are one part of NF1. The NHS lists other features: light brown patches of skin (café-au-lait spots), freckles in the armpits or around the tops of the legs, yellow-brown raised dots on the iris that do not usually affect vision, eye problems such as a squint or reduced vision, a large head and below average height, and learning difficulties. Several neurofibromas together with café-au-lait spots is a reason to ask a GP about NF1.

The NHS says how severe symptoms are usually depends on where the tumours are in the body and how big they are.

The NHS says NF1 is caused by an altered gene. Sometimes the altered gene is passed on to a child by one of their parents, but sometimes a child is born with NF1 even if the parents do not have it. If you have NF1, the NHS says there is a 1 in 2 (50%) chance of passing the affected gene on to any children.

Neurofibromas are not cancer. However, the NHS says that in NF1 some tumours can become cancerous and there is a higher risk of developing certain types of cancer, including breast cancer and brain cancer, and recommends that women with NF1 have a mammogram each year from the age of 40. Because of this, tell your doctor about any new symptoms or changes in existing ones, such as a lump that grows quickly or becomes painful.

If a GP thinks you or your child might have NF1, the NHS says they refer you to a specialist for tests. Tests that help confirm NF1 include eye tests to check vision, an MRI scan to check for tumours in areas such as the brain, spine and tummy, and genetic tests.

You are usually looked after by a team. The NHS says this may include a neurologist, an ophthalmologist and a dermatologist, and children also see a paediatrician.

See a GP if you think you or your child might have NF1. The NHS says to ask for an urgent GP appointment or get help from NHS 111 if you or your child keep getting headaches that do not go away or are getting worse, keep feeling or being sick, or have blurred vision or vision loss. For a child under 5 years old, call 111.

Nerve Tumours UK advises seeing a doctor if a lump becomes very large, twisted or red, or infected.

The NHS calls NF1 a lifelong condition that usually gets worse over time and affects everyone differently. Annual check-ups are recommended, children should have their eyes checked every year (adults every 2 years) and blood pressure should be checked every year. Large or facial tumours can also affect mood: the NHS lists depression, anxiety and low self-esteem as possible problems.

Nerve Tumours UK says it can be hard when people ask about your lumps, and suggests you might explain what they are, change the subject or walk away. There is no right or wrong way to respond, and its helpline and specialist NF nurses are available. The NHS also points to the Childhood Tumour Trust for children and young adults up to age 30.

On the NHS, a GP refers you to a specialist for tests and, in NF1, care is shared between several specialists. The NHS says care teams pass information to the National Congenital Anomaly and Rare Disease Registration Service, and you can opt out at any time. Removal of skin neurofibromas is usually carried out by NHS plastic surgery units, and complex cases go to the national NF1 clinics.

People who prefer to see a dermatologist or plastic surgeon privately for removal of neurofibromas can do so. Ask whether the clinician has experience of NF1, and bear in mind that new lumps can appear over time.