Diagnosis
To diagnose a malignant peripheral nerve sheath tumor (MPNST), a healthcare professional may start with an exam and imaging tests. To be certain whether something detected on those tests is cancer, the health professional may recommend a biopsy procedure to remove some tissue for testing.
Neurological exam
A neurological exam tests the brain and nerves to see how they're working. This exam may include checking your vision, hearing, balance, coordination, strength and reflexes. If you have trouble in one or more areas, this may give your healthcare professional clues about what's causing your symptoms. A neurological exam can't diagnose malignant peripheral nerve sheath tumors. But it helps your health professional understand whether your symptoms may be related to a nerve condition.
Imaging tests
Imaging tests make pictures of the body. The pictures might help healthcare professionals see the size of the MPNST and whether it has spread to other parts of the body. Tests might include:
On MRI scans, a malignant peripheral nerve sheath tumor may look like a growth that is wide in the middle and narrow at both ends. These tumors also can look round or have an irregular shape.
Biopsy
A biopsy is a procedure to remove a sample of tissue for testing in a lab. To get a tissue sample from a malignant peripheral nerve sheath tumor, the healthcare team may recommend surgery to remove some or all of the tumor. Sometimes a healthcare professional may put a needle through the skin to get a sample. Imaging tests help guide the needle to the right spot.
Healthcare professionals in the lab look at the sample to see if it is cancer. Other tests might give more details about the cancer cells. The healthcare team uses this information to make a treatment plan.
Grades
The cancer's grade tells the healthcare team how the cancer is likely to behave. To determine the grade for malignant peripheral nerve sheath tumors, healthcare professionals in the lab examine a sample of the cancer under a microscope. They look at how the cancer cells appear and how many cells are dividing. They also look at how much of the cancer contains dead cells. These features are used to assign a grade from 1 to 3.
MPNST grades include:
- Grade 1. The cancer is low grade and is likely to grow slowly.
- Grade 2. The cancer is intermediate grade and is likely to grow more quickly than grade 1 cancer.
- Grade 3. The cancer is high grade. It's more likely to grow quickly and to spread to other parts of the body.
Most malignant peripheral nerve sheath tumors are high-grade cancers.
Stages
The cancer stage tells the healthcare team about the size of the cancer and whether it has spread. The stage helps the care team make a treatment plan. MPNST stages are based on the size of the cancer, whether it has spread and the grade. This information can come from imaging tests, results from a biopsy and findings from surgery to remove the cancer.
MPNST is a type of soft tissue sarcoma. MPNST staging uses the same stages as soft tissue sarcoma. There are different sets of stages based on where the cancer happens in the body. Most malignant peripheral nerve sheath tumors happen in the arms, legs and trunk. The stages for these cancers are:
- Stage 1. The cancer is low grade and can be any size. At this stage, the cancer hasn't spread.
- Stage 2. The cancer is intermediate or high grade and is 5 centimeters (about 2 inches) or smaller. The cancer hasn't spread.
- Stage 3. The cancer is intermediate or high grade and is larger than 5 centimeters. It hasn't spread.
- Stage 4. The cancer has spread to nearby lymph nodes or to other parts of the body. When cancer spreads, it's called metastatic cancer. MPNST most often spreads to the lungs. It also can spread to the liver, bones and brain.
If your malignant peripheral nerve sheath tumor starts in a part of the body other than the arms, legs or trunk, your healthcare team may use a different set of stages.
Treatment
Treatment for malignant peripheral nerve sheath tumors (MPNSTs) often involves surgery to remove the cancer. Other treatments may include radiation therapy and chemotherapy.
Surgery
The goal of surgery for malignant peripheral nerve sheath tumors is to remove all of the tumor and some of the healthy tissue around it. Whether surgeons can remove the tumor completely may depend on the tumor's size and location.
To get all of the cancer cells, surgeons may need to remove nearby nerves or other structures. For tumors in the arms and legs, this sometimes means removing the arm or leg, though surgeons avoid this when possible.
Radiation therapy is sometimes used before surgery. This might help shrink the tumor and make it more likely that the tumor can be removed completely.
Radiation therapy
Radiation therapy treats cancer with powerful energy beams. The energy can come from X-rays, protons or other sources. During radiation therapy, you lie on a table while a machine moves around you. The machine directs radiation to precise points on your body.
For malignant peripheral nerve sheath tumors, radiation might be used after surgery. It can kill any cancer cells that might remain. Sometimes radiation is used before surgery.
Chemotherapy
Chemotherapy treats cancer with strong medicines. Not all malignant peripheral nerve sheath tumors respond to chemotherapy. This treatment might be an option when the cancer spreads. Chemotherapy may help slow the growth of the cancer and help with symptoms, such as pain.
Prognosis
The prognosis for malignant peripheral nerve sheath tumors (MPNSTs) varies widely. A cancer prognosis describes how likely it is that a cancer can be treated successfully or cured. It's based on what the healthcare team knows about the cancer, the treatment options and your overall health.
In general, malignant peripheral nerve sheath tumors that can be removed completely with surgery have the most favorable outlook. Removing all of the cancer lowers the risk that the cancer will come back or spread.
If you want to know more about your outlook or wonder what your cancer means for your life expectancy, talk with your healthcare team. Your healthcare professionals can explain what factors they consider when thinking about your prognosis.
Your healthcare team may consider:
- The cancer's grade. High-grade cancers tend to grow more quickly and are more likely to spread.
- The cancer's location. Some tumors, such as those growing in the head and neck area, may be more difficult to remove completely.
- The cancer's size. Larger tumors have a greater risk of spreading.
- Results of surgery. The outlook is generally more favorable when surgeons can remove all of the cancer.
- Whether the cancer has spread. The cancer may be more difficult to control if it spreads to other parts of the body.
These factors provide general information about prognosis, but they cannot predict exactly what will happen for one person. Your healthcare team can explain what these factors mean for you.
Preparing for your appointment
If you have symptoms that worry you, make an appointment with a doctor or other healthcare professional.
People who are diagnosed with malignant peripheral nerve sheath tumors (MPNSTs) may receive care from:
- Neurologists. These doctors diagnose and treat nervous system conditions.
- Neurosurgeons. These surgeons do operations involving the nerves.
- Oncologists. These doctors treat cancer.
- Orthopedic surgeons. These surgeons do operations involving the bones.
Because appointments can be brief and because there's a lot to discuss, it's a good idea to be prepared. Here's some information to help you get ready and know what to expect.
What you can do
Ask a family member or friend to go with you. Sometimes it can be hard to remember all the information given during an appointment. Someone who is with you may remember something that you missed or forgot.
Make a list of:
- Your symptoms, and when they began.
- All medicines, vitamins and other supplements you take, including doses.
- Questions to ask your healthcare professional.
Some questions to ask at your first appointment include:
- What may be causing my symptoms or condition?
- Are there other possible causes?
- What tests do I need?
- What's the next step in finding my diagnosis and deciding on treatment?
- Are there restrictions that I need to follow in the meantime?
Questions to ask a specialist:
- Do I have a malignant peripheral nerve sheath tumor?
- What are the goals of treatment for me?
- What treatment do you suggest?
- Do I need to begin treatment right away?
- I have other health conditions. How can I manage them together?
- What are the possible side effects of treatment?
- If the treatment doesn't work, what's next?
- What is the outlook for my condition?
Be sure to ask other questions you have.
What to expect from your doctor
Your healthcare professional is likely to ask you questions, including:
- Have your symptoms changed over time?
- Does anything make your symptoms better?
- Does anything make them worse?
- Have you been told you have other medical conditions?