A patient’s guide to Nerve Sheath Tumours

Plural: schwannomata

A schwannoma (sh-won-oma) is a tumour of the tissue that covers nerves, called the nerve sheath. These tumours develop from a type of cell called a Schwann cell, which gives them their name. A schwannoma is not a cancerous lump (it is benign). They are one of the most common lumps to be found in nerves, even though they are still quite rare. (https://www.cancerresearchuk.org/about-cancer/other-conditions/ schwannoma/about)

A schwannoma often has no underlying cause, but they can be linked to conditions which run in families such as ‘Schwannomatosis.’ This is where your body grows many of these lumps often in one limb or one side of the body.

Your symptoms will be dependent on the site and size of the schwannoma. You may have no symptoms or your presentation may be with a slow growing lump. Other symptoms include:

• Sharp pain on applied pressure of the lump
• Pins and needles in the affected limb when the lump is pressed

Diagnosis is based on your symptoms, clinical examination findings and often a MRI scan.

No, a schwannoma is not cancerous. They are slow growing, benign lesions. However, it is not possible to say for absolute certainty that your lump is a schwannoma until it has been removed and sent to the lab for histology (looking at the lump under a microscope to confirm what it is). The results of this are usually back by your follow up clinic two weeks after surgery.

Your schwannoma can be left alone (managed non-operatively) and you will be reviewed in our clinic. If your lump is causing you pain and tingling, we may offer to cut out the lump. We may also suggest it is taken out to make sure we know what it is. The doctors will help you come to a decision about your care.

The aim of removing the lump is to improve your symptoms whilst providing a definitive diagnosis of what the lump is.

Surgical excision (taking away the lump) of a schwannoma usually involves admission to hospital as a day case (home on the same day) or as a one-night stay. This is at the Stanmore site (HA7 4LP). You will require a general anaesthetic and the surgery takes around 1-2 hours.

During the operation we carefully dissect (remove) the schwannoma from within the nerve itself. The aim is to preserve the rest of the nerve cells that make up the nerve.

The skin is closed with dissolvable sutures (they do not need to be removed).

All operations have risks. The overall benefit and risks will be discussed with you individually again on the day of surgery. Your absolute risk varies depending on where your schwannoma is located and your other medical history. Possible risks include (but are not limited to):

• Pain. You may experience a slight increase in your pain as during removal of the tumour the nerve can be stretched. This usually settles within a few weeks.
• Infection. Occurs in less than 1%. The operation is performed under sterile conditions. Despite this, infection may still occur. This is treatable with antibiotics.
• Bleeding. It is very rare for a blood transfusion to be required. More commonly, a haematoma (or collection of blood under your skin) may form.
• Damage to the nerve itself. Occurs in less than 1%. The outcome of this depends on where your schwannoma is located. It may result in changes to sensation or weakness in particular muscles. The Peripheral Nerve Injury Unit is a specialised centre that manages schwannomata daily and hence this risk is much lower than in other centres. The risk of damage to the nerve is slightly higher if the schwannoma has been biopsied already.
• Damage to other surrounding structures.
• Scarring. Occasionally the scar itself can be painful.
• Inability to remove the tumour. Very occasionally, during the operation, the schwannoma is too difficult to remove without causing significant damage to the underlying nerve. After careful consideration the decision not to remove the schwannoma may be made if the risks outweighed the benefits. This is exceptionally rare.
• Recurrence (a tumour growing back). This is very rare and occurs in less than 0.1%.
• Deep vein thrombosis. This is a blood clot in a vein due to the surgery. It can cause leg swelling and pain. Very occasionally the clot can travel to the lungs and affect your breathing. This is known as a pulmonary embolus (PE) and can be fatal. The risk of this is low as usually the procedure is a day case or admission for one night. Wearing specialised stockings during your stay will reduce this. Mobilising early is also one of the best ways to prevent blood clots from forming.
• Risks of a general anaesthetic. This will be discussed with you by the anaesthetist on the day of surgery.

You may be able to go home on the day of surgery or the following day. This depends on your other medical problems, your support at home and the other patients that will be operated on that day. It is not possible to confirm what time exactly your surgery will be as this can change at short notice depending on emergencies. On the morning of the surgery we will be able to give you a better idea of when your operation will be.

The wound usually takes 2 weeks to heal. It is important during this time that you keep the dressing clean and dry at all times. Try not to change the dressing unless it is absolutely necessary.

You will be reviewed two weeks after surgery in our Dressings Clinic at Bolsover Street. This is run by our specialist nurse and junior doctors on the team. They will see how you are progressing and review the healing of the wound. The results of the histology are usually back at this time. Sometimes you can be safely discharged at this point or some patients will be seen again by the consultant or the registrars at approximately 3 months after the operation.

People who smoke are at higher risk of developing complications with their lungs and circulation. Smoking also affects wound healing. Stopping smoking before surgery, even for a short time, can reduce your risks associated with surgery and improve your surgical success.

Once we have offered you surgery in clinic we will call you with a date for surgery. The timing of this will vary depending on the urgency of your case. Our scheduler will give you a date for surgery and will send written confirmation of this. After a date has been set you will be called by our pre-operative assessment team. Some patients may be asked to attend a screening in person. If you are on any regular medication, please ask the pre-operative assessment staff what medication you can take on the day of surgery.

Please read this webpage in conjunction with “A Patient’s Guide to Admission” or visit: www.rnoh.nhs.uk/patientsvisitors/ information-guides.

You will be admitted to hospital on the day you have your surgery. Occasionally, it is necessary for patients to have further tests before surgery. If this is the case, you will be asked to come in the day before. On admission, you will see several members of the treating team who will complete final checks to make sure you are fit for surgery. If you have any questions, please ask a member of staff.

The Stanmore Building, Royal National Orthopaedic Hospital NHS Trust, HA7 4LP

If you are unwell in the days prior to surgery or if there are any changes in your medical condition, such as dental or urinary infection, or infected cuts or ulcers on your skin please let us know as soon as possible. Your operation may need to be rescheduled, however this is in your best interests to reduce the risk of developing post-operative infection.

Before the operation one of the surgical team will discuss the procedure with you and answer any questions you may have. You will be asked to sign a form giving consent to the operation. The anaesthetist will visit you before your operation to discuss your anaesthetic options.

You will be told not to eat for approximately six hours and drink for two hours prior to your operation, depending on the anaesthetist’s instructions. Failure to follow these instructions will result in your operation being delayed or even cancelled. Our porters will take you to the operating theatre and a nurse will accompany you and hand you over to the care of the theatre team.

Peripheral Nerve Injury Unit Coordinator: 020 3947 0051

Clinical Nurse Specialist: Dennis Hazell

E-mail: rnoh.cns-pni@nhs.net

www.rnoh.nhs.uk/services/peripheral-nerve-injury-unit