If you or a loved one has been diagnosed with a malignant peripheral nerve sheath tumor, or MPNST, you may have a lot of questions about what this condition means for you or them. Experts at the OSUCCC – James are leading the way with groundbreaking research to better understand these conditions. MPNST is a type of sarcoma.
What is malignant peripheral nerve sheath tumor?
Malignant peripheral nerve sheath tumors are rare and aggressive types of soft tissue sarcomas. These cancerous tumors occur deep in the tissues that surround and protect your peripheral nerves. Peripheral nerves are located outside of the brain and spine. While cancer can occur anywhere in the body, MPNST most commonly forms in the major nerve trunks of the abdomen or extremities (arms or legs). Nerve trunks are the main stems from which nerves branch out into other parts of the body. MPNST most commonly occurs in young adults to middle-aged adults.
What causes MPNST?
Currently, there is no exact known cause for malignant peripheral nerve sheath tumors. Like most sarcomas, researchers are still learning about why some of these cancers occur in some individuals and not others.
MPNST forms when cancerous cells in the peripheral nerve lining grow out of control and invade healthy surrounding tissues. Our body’s normal cells contain instructions called DNA to help them grow and reproduce at a healthy rate. However, over time, these cells can mutate (change) and generate “bad” instructions for reproduction. When this occurs, MPNST can form and grow in the body’s soft tissues.
MPNST risk factors
Initial research has shown that there are some risk factors that could increase the likelihood of whether you could develop MPNST. Risk factors are anything that could increase the likelihood of you developing a condition. These factors are things you can or can’t influence.
Current genetic research has shown these tumors are more commonly found in those who have neurofibromatosis type 1 (NF1) when compared to others who do not. NF1 is a genetic condition. Research estimates that about one quarter to one half of all people who develop MPNST also have NF1. There is some research that indicates you could be at an increased risk for developing a tumor if you have had previous radiation exposure as well.
However, just because you may have NF1 or have previous radiation exposure doesn’t mean you’ll get an MPNST. It’s important to talk to your doctor to understand your risk of developing any condition.
MPNST symptoms
At first, these tumors may not have any symptoms. However, as they grow and get larger, you could experience some new or worsening symptoms.
Commons symptoms of MPNST may include:
- Lump or bump under the skin that gets larger over time
- Pain near the lump or bump
- Weakness in the limbs
- Burning pain that radiates down the arm or leg
These symptoms are associated with other illnesses. Just because you may have one or all of them doesn’t mean you have MPNST. Be sure to talk to your doctor about any unusual symptoms you may be experiencing.
How is malignant peripheral nerve sheath tumor diagnosed?
Experts at the OSUCCC – James work together using a multidisciplinary approach. If your doctors suspect you have MPNST, they will order a series of tests to determine the exact cause. Some of those tests may include imaging tests and/or biopsies of the suspected tumor.
Some of the imaging tests they may order include:
- Magnetic resonance imaging (MRI)
- Computed tomography (CT) scan
- Positron emission tomography (PET) scan
If your doctor orders a biopsy, they will use a needle to take a sample of tissue from the suspected tumor. An OSUCCC – James expert pathologist will then take the sample and analyze it in the lab. The sample will be reviewed and classified. If the pathologist and your doctors determine MPNST is present, the team will create a recommended treatment approach to address your specific tumor.
MPNST treatment
Treatment for MPNST will be dependent on the size and location of the tumor. Using a multidisciplinary approach at the OSUCCC – James, your team of surgical oncologists, radiation oncologists and other subspecialists will create a customized plan for you.
Currently, the ideal treatment for MPNST is complete surgical removal of the tumor. If an MPNST occurs in the soft tissues of the arms or legs (extremities), the tumor is removed with a normal cuff of surrounding tissues to provide the best chance for complete removal. Your surgeon will spare as much of the functional tissue as possible so that the impact on your daily activities is lessened. When MPNST occurs in the abdominal and pelvic organs, the surgeon will remove the affected organ and adjacent structures needed to remove the entire tumor. Some organs such as the stomach or major blood vessels may need to be reconstructed to maintain bodily function.
When a nerve needs to be removed to treat an MPNST, our reconstructive surgeons perform a targeted muscle reinnervation (TMR). This can help alleviate post-operative pain; they may even potentially reconstruct the nerve if the length of the nerve is not too large or radiation therapy has been used to decrease the risk of the tumor returning.
In the event total removal of the tumor isn’t possible, your doctors may recommend radiation therapy to help shrink the tumor before surgery. After surgery, your doctors may recommend radiation therapy to help prevent the tumor from coming back. MPNST is not very responsive to chemotherapy, so it’s usually only used when the cancer has spread (metastatic).
If you have received an MPNST diagnosis, if you want a second opinion or if you just want to speak to a sarcoma specialist, we are here to help you. Call 800-293-5066 or 614-293-5066 to make an appointment.
Additional Resources
Types of Sarcoma
Soft Tissue Sarcoma
Prevention
Screening and Diagnosis
Clinical Trials