Malignant Peripheral Nerve Sheath Tumor
What is Malignant Peripheral Nerve Sheath Tumor?
Malignant Peripheral Nerve Sheath Tumor, or MPNST, is a cancer of the cells that form the sheath that covers and protects peripheral nerves. Peripheral nerves are those outside of the central nervous system (brain and spinal cord). MPNST is a type of sarcoma. This cancer grows in the soft tissues of the body, such as muscle, fat, tendons, ligaments, lymph and blood vessels, nerves, and other tissue that connects and supports the body. MPSNST grows quickly and can spread to other parts of the body.
How common is Malignant Peripheral Nerve Sheath Tumor?
Sarcomas are rare cancers and MPNST is a rare type of sarcoma, making up 5% to 10% of sarcoma cases.
MPNST is most common in young adults and middle-aged adults. MPNST is more common in people with a genetic condition called neurofibromatosis type 1 (NF1). About 25% to 50% of people with MPNST have NF1. And about 8% to 13% of people with NF1 will get MPNST in their lifetime.
How is Malignant Peripheral Nerve Sheath Tumor diagnosed?
Some people with MPNST do not have symptoms at first. Later, when the tumor gets larger, symptoms can include:
- a growing lump under the skin
Imaging: If you have symptoms of MPNST your doctor will use scans such as MRI, CT, and PET to see where the tumor is and how big it is. They will also check for signs that the tumor has spread to other parts of the body.
Biopsy: To check if the tumor is MPNST your doctor will do a biopsy, taking a small sample from the tumor with a needle. An expert, called a pathologist, will study cells from the sample under the microscope and run other tests to see what kind of tumor it is.
How is Malignant Peripheral Nerve Sheath Tumor treated?
Surgery: Once MPNST is diagnosed, you may have surgery to remove the tumor and surrounding tissue. But sometimes surgery is not an option. In that case, your doctor will discuss other options with you.
Radiation therapy: Radiation therapy can be used before and after surgery.
Chemotherapy: If the tumor can’t be safely removed by surgery, chemotherapy can be used to shrink it and make it easier to remove. Sometimes chemotherapy is used with radiation. Chemotherapy can also be used when MPNST has spread to other parts of the body.
It is important to talk with a team of specialists to decide the right treatment for you. You can contact MyPART for help finding experts near you.
Does Malignant Peripheral Nerve Sheath Tumor run in families?
In rare cases, members of the same family may have MPNST. People who have NF1 plus a family history of MPNST may be more likely to get MPNST.
How does Malignant Peripheral Nerve Sheath Tumor form?
MPNST forms when the sheath cells that cover nerves grow and divide more than normal. The fact that almost half of MPNSTs occur in people with neurofibromatosis type 1 may give scientists some clues. Scientists are always working to understand how cancer forms, but it can be hard to prove.
What is the prognosis for someone with Malignant Peripheral Nerve Sheath Tumor?
The estimate of how a disease will affect you long-term is called prognosis. Each person is different and prognosis will depend on many factors, such as:
- Where the tumor is in your body
- If the cancer has spread to other parts of your body
- How much of the tumor was taken out during surgery
If you want information on your prognosis, it is important to talk to your doctor. Also, NCI has resources to help you understand cancer prognosis.
The five-year survival rate for people with MPNST is between 23% and 69%. How long someone with MPNST lives depends on the size of the tumor and where it is in the body. People with smaller tumors tend to live longer than people whose cancer has spread to other parts of the body.
It is very important to work with a team of experts as soon as possible after diagnosis to improve your chances of survival. You can contact MyPART for help connecting with experts in MPNST.