Malignant peripheral nerve sheath tumour (MPNST)

Malignant peripheral nerve sheath tumours (MPNSTs) is rare. It is a type of peripheral nerve sheath tumour that is cancerous (malignant).

Most peripheral nerve sheath tumours are not cancerous (benign). A tumour is a lump or growth in the body.

One type of non cancerous peripheral nerve sheath tumour is called a schwannoma.

This information is about peripheral nerve sheath tumours that are cancerous (malignant).

What is a malignant peripheral nerve sheath tumour?

Malignant peripheral nerve sheath tumours are a type of peripheral nerve sheath tumour. These cancers begin in the layer (nerve sheath) that cover the peripheral nerves. Peripheral nerves send messages between the brain and spinal cord and the rest of the body.

MPNST are rare in the general population. It can happen in people with neurofibromatosis type 1(NF1). They can grow anywhere in the body. The most common sites are the:

• legs
• deeper tummy (retroperitoneum)

Other types of peripheral nerve sheath tumours 

Other types that may be cancerous (malignant) include:

• melanotic malignant nerve sheath tumour
• granular cell tumour
• perineurioma

Tests to diagnose malignant peripheral nerve sheath tumour

Your specialist will examine you and then you may need other tests which can include:

• blood tests
• ultrasound scan
• biopsy
• MRI scan
• CT scan
• X-ray

Treatments for malignant peripheral nerve sheath tumour

Malignant peripheral nerve sheath tumours can be difficult to treat.

Surgery 

The main treatment is surgery. Your surgeon aims to remove as much of the cancer as possible and the surrounding tissue. 

Radiotherapy

You might have radiotherapy before surgery. Radiotherapy aims to shrink the cancer, making it easier to remove. This is called neoadjuvant treatment. 

Radiotherapy after surgery can kill any cancer cells left behind. This when your surgeon wasn't able to remove all the cancer. It also aims to lower the risk of sarcoma coming back. This is called adjuvant treatment. 

Chemotherapy

Malignant peripheral nerve sheath tumours don't respond very well to chemotherapy. Chemotherapy may be used to try to shrink the tumour or slow its growth, but it is usually unlikely to cure it. 

Targeted therapy

You might have treatment with a targeted drug as part of a clinical trial. Talk to your specialist to find out more.

Malignant peripheral nerve sheath tumour that comes back

A malignant peripheral nerve sheath tumour can come back in the same place. This is called local recurrence.

Your surgeon aims to remove all the cancer during surgery. Sometimes this isn't possible. It depends on the size and position of the sarcoma. Occasionally there are microscopic traces of cancer left behind. This is enough for it to grow into a new tumour.

It can be more difficult to treat if the sarcoma comes back. You might have surgery again if it is possible to remove the new tumour. You might also have radiotherapy again depending on the previous radiotherapy dose.

Coping

Coping with a diagnosis of a rare cancer can be especially difficult. Knowing more about your sarcoma and its treatment can make it easier. It can help you to make decisions and cope with what happens.

Sarcoma UK has support and information for people affected by soft tissue and bone sarcoma.

The Rare Cancer Alliance offer support and information to people with rare cancers.

Talking to other people who have the same thing can also help.

Our discussion forum Cancer Chat is a place for anyone affected by cancer. You can share experiences, stories and information with other people who know what you are going through.