​Schwannoma (Neurilemmoma)​​


Schwannoma (Neurilemmoma) are benign tumours of the nerve sheath, which are cells and tissues covering the nerves. It is also known as schwannoma as the tumours arise from Schwann cells, which produce the myelin sheath that covers nerve fibres.

The peripheral nervous system is the network of nervous tissues outside the brain and spinal cord. Neurilemmomas may affect any location in the peripheral nervous system, for instance, the major nerve of the leg (the sciatic nerve), the nerves at the top of the arm (the brachial plexus), the lower back (the network of nerves called the sacral plexus) or any other network of nerves for a body part.

There is no known cause of schwannomas and these tumours are usually benign (not cancerous). The most common type of benign schwannoma is the acoustic neuroma, which affects the nerves that control hearing and may cause deafness. Only very few of the schwannomas become malignant and cancerous. The tumour cells grow very slowly with neurological symptoms (symptoms due to a nerve being affected) show up after many years. In some cases, a palpable mass that can be felt may be present.​​

Symptoms of schwannoma will vary, depending on which nerve the tumour has formed on. If a schwannoma occurs in the sciatic nerve, you may experience lower back pain or in the legs. If it affects the nerves to the arms, you will experience pain and numbness in your arms.

The following are the general signs and symptoms:

  • A painful lump felt on palpation (feeling with hands and fingers)

  • Altered sensations in the affected body part 

  • Numbness​

Because schwannomas grow slowly, these can exist for years without producing symptoms. The earlier the diagnosis is made, the better the chances that the tumour can be treated in time before it causes any neurological symptoms.

Therefore, if you feel the presence of a tender mass anywhere along your legs or arms, or experience any of the symptoms described above, consult our neurologists working for the Mind and Brain Service Line of The Aga Khan University Hospital.

Your time with your doctor may be limited, so make sure to prepare for your visit beforehand. H​ere are some tips to help get you started​

Besides taking a complete medical history involving details of your symptoms, and a physical examination in which your doctor will look for palpable masses or lumps, the following tests will be used to confirm the diagnosis of schwannoma:

  • X-rays, to detect presence of an abnormal mass

  • Magnetic resonance imaging (MRI) which uses large magnets to create images of internal organs and structures within the body. The MRI scan will help your doctor evaluate if any problems with spinal cord or nerves exist.

  • Ultrasounds, to develop images of the inside​s of the body

  • Blood and laboratory tests to test for levels of blood components 

  • A biopsy of a sample of the tumour to rule out if its cancerous


Surgery is generally a recommended treatment option for treating schwannomas as not only does it remove the growth, but also relieves pressure on the spine and nerves caused by the tumour.

Neurological surgeons may also use stereotactic radio surgery (highly targeted radiation beams from multiple angles) to treat schwannomas in cases where surgery is not an option.

In case the tumour has become malignant, radiotherapy or chemotherapy may be considered to stop the growth of the tumour cells. Chemotherapy may not be very effective with slow-growing schwannoma cells as it targets rapidly growing cells.

Please click here for some guidelines on "what to do before your surgery". ​

Please click here for some guidelines on "what to do on the day of your surgery". ​

The success of a schwannoma surgery will depend on your age, overall physical health, and the size and location of the tumour. There are risks that the tumour may not have been completely removed because of risks to other surrounding organs or to the nerve. In such a case, there is a possibility that the schwannoma may return, as even microscopic traces are enough for it to grow into a new tumour.

Please click here for some guidelines on "what to do after your surgery" ​

The Aga Khan University Hospital offers various support services to help with managing or recovering from the disease or condition. These include but are not limited to nutrition, physiotherapy, rehabilitation, specialized clinics and some patient support groups. Your doctor or nurse will advise you accordingly.

The Aga Khan University Hospital offers financial assistance to those who are in need and fulfil the eligibility criteria. For further information, you can contact the Patient Welfare Department. You can find the contact number of the Patient Welfare Department in the 'Important Numbers' section on the website homepage.

The financial counselling staff is available during office hours, at the main PBSD (Patient Business Services Department), to answer your financial queries on treatments' costs and authorize admissions on partial deposit as per hospital policies allow. The financial counsellor in the emergency room is open 24/7. You can find the contact number of the Patient Business Services in the 'Important Numbers' section on the website homepage.

Your doctor and or nurse will give you specific instructions about the prescribed medication. Please ensure that you take or use the prescribed medicine as advised. It can be dangerous to your health if you self-prescribe. Please inform the doctor or nurse beforehand if you have experienced any adverse reactions to any medications in the past. If you experience any symptoms of drug poisoning, overdose or severe reaction please contact the Pharmacy Service at The Aga Khan University Hospital immediately. You can find the contact number of the Pharmacy Services in the 'Important Numbers' section on the website homepage.




The information provided on our website is for educational purposes and not intended to be a substitute for medical advice, diagnosis or treatment. You should always seek the advice of your doctor or other healthcare professional provider.