Malignant peripheral nerve sheath tumor (MPNST)

Malignant peripheral nerve sheath tumors (MPNST) are a type of soft tissue sarcoma. Soft tissue sarcomas are cancers that grow in soft tissues of the body like fat, muscles, blood vessels and nerves. MPNSTs grow on the nerve sheath, the protective covering made of myelin that grows around the outside of your nerves.

What is a malignant peripheral nerve sheath tumor (MPNST)?

Malignant peripheral nerve sheath tumors (MPNST) are a rare type of cancerous tumor. These peripheral nerve tumors are most often found on larger nerves such as those in your arms, legs or pelvis. They may occur on your sciatic nerves, which branch off from your spine and travel down the back of your legs.

A small number of MPNST cancers may grow from previously benign neurofibroma or schwannoma tumors.

When a malignant peripheral nerve sheath tumor grows, it damages the myelin of the nerve sheath and disrupts the messages that travel through nerves to and from your central nervous system (brain and spine). They grow quickly and may be resistant to treatment.

Understanding malignant peripheral nerve sheath tumor symptoms

Symptoms of malignant peripheral nerve sheath tumors may not appear when tumors are still small. Common symptoms of larger tumors include:

• Pain, tingling or weakness in the affected area
• Noticeable growths under the skin
• Changes in sensitivity to touch, temperature or pain

Malignant peripheral nerve sheath tumor risk factors

These tumors are most prevalent in young and middle-aged adults, with about half of cases associated with a genetic condition called neurofibromatosis type 1. Previous radiation exposure, from treatment or from the environment, also increases the risk of developing these tumors. However, some cases occur randomly without identifiable risk factors.

How is a malignant peripheral nerve sheath tumor diagnosed?

Diagnosing MPNST requires a thorough evaluation. There are many conditions that cause similar symptoms. Your doctor will conduct a comprehensive physical examination and will want to know about your symptoms and medical history.

Testing may include assessing your reflexes and movements and genetic testing for neurofibromatosis type 1. Imaging tests like MRI, CT or PET scans will be used to locate tumors and see how big they are or if they’ve spread to other body parts.

Your doctor will be likely to order a biopsy, either through needle extraction or surgical means, to allow microscopic and molecular evaluation of tissue as an aid in diagnosis.

How is a malignant peripheral nerve sheath tumor treated?

The primary goal of malignant peripheral nerve sheath tumor treatment is tumor removal. Surgery aims to remove as much of the tumor as possible while avoiding damage to the affected nerves. When an MPNST affects an arm or a leg, amputation is sometimes needed.

In cases where complete removal of the tumor isn't feasible, chemotherapy or radiation therapy may be used before surgery to shrink the tumor and make it easier to remove. Post-surgery, these treatments may also target any remaining tumor or cancer that has spread to other parts of the body.

MPNST cancers tend to return after being removed through surgery or other treatments. When they return, they’re also known to spread (metastasize) to the lungs. If your cancer recurs, your team of caregivers will work with you to decide what to do next.

Comprehensive support during treatment

At Aurora Health Care, your treatment for neurological cancer will be provided by a multidisciplinary team that addresses both your medical treatment and your emotional well-being throughout treatment and recovery. We offer:

• Physical therapy to maintain strength and range of motion
• Nutritional guidance
• Spiritual and emotional counseling
• Support for sexual health
• Palliative care and hospice care
• Integrative cancer care for stress, pain, fatigue and nerve damage

Your journey with Aurora Health Care is not just about treating disease but also about providing care to enhance your quality of life.