Schwannoma: symptoms, causes and treatment

The NHS says an acoustic neuroma may not cause obvious symptoms at first, and when symptoms appear they tend to develop gradually. Cancer Research UK mentions difficulty hearing on the phone and in crowded places as a typical early sign. A large tumour can press on structures nearby and cause further problems.

• Hearing loss, usually in one ear.

• Tinnitus: ringing, buzzing or other sounds from inside the body.

• Vertigo, dizziness or a sense of lost balance.

• With larger tumours: persistent headaches, blurred or double vision, numbness, pain or weakness on one side of the face, problems with limb co-ordination, voice changes or difficulty swallowing.

• For schwannomas elsewhere: a lump, pain, aching, burning, pins and needles, numbness or weakness in the area served by the nerve.

Nerves are wrapped in a protective covering made by Schwann cells. A schwannoma is a tumour that develops from those cells. Cancer Research UK stresses that it is non-cancerous, and the NHS adds, for the vestibular type, that benign brain tumours usually grow slowly over many years and do not spread to other parts of the body.

Rarely, Cancer Research UK says, a schwannoma may change into a malignant peripheral nerve sheath tumour. That is unusual, and is one reason the team keeps an eye on any tumour that behaves unexpectedly.

The vestibular schwannoma is the one most people have heard of. The NHS says it affects adults aged 30 to 60 and usually has no obvious cause, although a small number of cases result from a genetic condition called neurofibromatosis type 2. Cancer Research UK says these tumours are usually diagnosed in older adults and grow over several years.

Other sites include nerves in the head that control facial movement and feeling or swallowing, the spinal nerves, and peripheral nerves outside the brain and spine. Some people have no symptoms from them at all and learn of the tumour incidentally on a scan.

The NHS notes that acoustic neuromas can be difficult to diagnose because the symptoms can be caused by other conditions such as Ménière's disease. If a GP suspects one, you will be referred for hearing tests to check whether hearing problems come from a nerve problem, and an MRI scan, which gives a detailed picture of the inside of the head. A CT scan may also be used.

For schwannomas elsewhere, Cancer Research UK says you usually have an MRI scan, and may also have an ultrasound scan (often for tumours just under the skin), a CT scan or a hearing test. A biopsy or surgery to remove the whole tumour can confirm the diagnosis, with a pathologist examining the tissue.

The NHS lists three main options for an acoustic neuroma, depending on the size and position of the tumour, how fast it is growing and your general health: monitoring with regular MRI scans, surgery to remove all or part of the tumour, and stereotactic radiosurgery, a precise beam of radiation that aims to stop it growing. All carry risks, for example facial numbness or an inability to move part of the face.

Cancer Research UK says the main treatment for schwannoma generally is surgery, and the type depends on where the tumour is. Your specialist may begin by monitoring you carefully with regular examinations and tests. Targeted radiotherapy is another option, and pain control is part of treatment where needed.

The NHS says a large acoustic neuroma can be serious because it can sometimes cause a life-threatening build-up of fluid in the brain (hydrocephalus), but it is rare for them to reach this stage. Many grow very slowly or not at all, and those that grow faster can be treated before they become too big.

Even after treatment, hearing loss and tinnitus can persist and affect work, communication and driving; the NHS says these may need further treatment. Regular MRI scans normally continue to check for regrowth or recurrence.

See your GP if you have persistent or troublesome symptoms that you are worried could be caused by an acoustic neuroma, as the NHS advises. For hearing, the NHS says to ask for an urgent GP appointment or get help from NHS 111 if you have sudden hearing loss in one or both ears, and RNID says sudden hearing loss can be a medical emergency with a very short window for treatment to work. If you cannot reach a GP or NHS 111, go to A&E.

The NHS says a large acoustic neuroma can sometimes cause a life-threatening build-up of fluid in the brain (hydrocephalus), though it is rare for them to reach this stage. The NHS page does not list emergency thresholds, so use the usual rules: call 999 for sudden severe headache, repeated vomiting, worsening drowsiness or confusion, or sudden weakness of the face or limbs.

Cancer Research UK says adults or children with multiple schwannomas, and children with a single one, may be tested for NF2-related schwannomatosis or non-NF2 schwannomatosis. Those are separate conditions, covered in their own guides, and are usually looked after by specialist centres.

The NHS route for a suspected acoustic neuroma is a GP referral for hearing tests and an MRI scan, then specialist care. The NHS says the choice between monitoring, surgery and stereotactic radiosurgery depends on the size and position of the tumour, how fast it is growing and your general health. Cancer Research UK says that for schwannomas elsewhere, treatment is planned by a specialist team and may begin with careful monitoring.

Private ENT, neurosurgery and imaging services can shorten waits for assessment and scans. Because the options are specialist and often involve a multidisciplinary team, ask who will coordinate your follow-up MRI scans and make sure results are shared with your GP.