Nerve Sheath Tumors
he nerve sheath is a myelin connective tissue that protects and insulates the fibers of peripheral nerves, which are the nerves that either arise from the brain or the spinal cord and transport messages to the skin, muscles, or internal body organs. When there’s abnormal increased cell growth within the nerve sheath, a nerve sheath tumor develops. It’s often accompanied by symptoms of pain, itchiness/burning sensation, and weakness in severe cases. Tumors of a nerve sheath are most prevalent in young adults and middle-aged individuals.
Most nerve sheath tumors are benign which means they are non-cancerous. Most often nerve sheath tumors are slow-growing and do not spread to other parts of the body. Though malignant peripheral nerve sheath tumors (MPNST) can form, they are rarely diagnosed.
The Centers for Neurosurgery, Spine & Orthopedics in New Jersey provides accurate diagnoses and treatment for nerve sheath tumors. With a team of experienced neurosurgeons who provide comprehensive treatment, CNSO’s high-quality care is available throughout Northern New Jersey with offices in Paramus, Wayne, Jersey City, Morristown, and West Orange.
Symptoms and Risk Factors of Nerve Sheath Tumor
Most individuals with nerve sheath tumors do not experience any symptoms. But once the tumor reaches a certain size, it starts to compress the nearby nerve and will begin to manifest the following signs:
- Tingling, numbness, and itchiness
- A noticeable lump under the skin
The causes of nerve sheath tumors are not well known. Many of them are sporadic and develop over the 5th or 6th decade of life without an identifiable trigger. Neurofibromatosis Type I and Type II, as well as schwannomatosis, are conditions that predispose a patient to the development of a nerve sheath tumor (NST).
There are additional factors that can cause a person to be at risk for developing a malignant nerve sheath tumor. They include:;
- Previous radio-therapies – If one has previously undergone radiation cancer treatment, MPNST can develop in the target body part after one or two decades.
- Benign nerve sheath tumors – These are non-cancerous tumors, such as neurofibroma and schwannoma that could develop into MNSTs later in life.
Types of Nerve Sheath Tumors
A Schwannoma is one of the most common non-cancerous tumors. It typically begins as a small bundle (fascicle) within the main nerve cell. As it grows, it displaces other parts of the cell and can enlarge and assume abnormal shapes. The tumor known as the dumbbell tumor, which usually affects the pelvis and spine, is an excellent example of schwannoma. Rarely does a schwannoma grow in two parts of the body simultaneously. Only in unique situations can a patient have them in several body parts, such as arms and legs, appearing as masses or lumps beneath the skin.
A rare type of schwannoma known as an acoustic neuroma grows near the brainstem and can cause several health problems. For instance, a patient might lose their ability to maintain proper balance or hearing. If treatment is not sought, the condition can affect the surrounding nerve cells and as well as compress the brainstem.
A Neurofibroma arises from the center of a peripheral nerve. It’s commonly reported among individuals with a genetic condition called neurofibromatosis 1 (NF1) or 2 (NF2). Most of the time it manifests as a slightly discolored lump on the skin. It can also occur as an optical nerve tumor (in the eye) or it can affect the curvature of the spine. This is a condition known as scoliosis.
Perinuerioma is a rare nerve sheath tumor which can grow inside and outside the nerve cell. When it grows outside the nerve, it presses against the neuron, which can cause radiculopathy: pain, sensory changes, and tingling. They may also grow within fat cells, forming small lumps called lipomas and ganglion cysts. Intraneural perineurioma commonly occurs among children and young adults. It advances gradually, progressively causing loss of sensation in the limbs and can lead to severe weakness in some cases.
Malignant Peripheral Nerve Sheath Tumor (MPNST)
A malignant nerve sheath tumor is a rare type of sarcoma comprised of cancerous cells that affect the nerve sheath. It is a fast growing tumor, that spreads to other parts of the body, such as ligaments, fat cells, muscles, tendons, and blood cells, and causes rapidly progressive symptoms. MPNST can pose serious health threats, and it’s critical to seek treatment immediately.
MPNST is a rare type of sarcoma that accounts for only 5%-10% of the total sarcoma cases. It commonly affects the youth and middle-aged individuals with a genetic condition called neurofibromatosis type 1 (NF1). About half of MPNST patients have NF1, and virtually 15% of persons with NF1 develop MPNST in their lifetime.
Diagnosis of Nerve Sheath Tumor
Based on physical examination, a neurosurgeon may suspect that an individual has a nerve sheath tumor. They’ll then conduct diagnostic studies to identify the exact type of tumor in order to offer proper treatment. Here are the standard diagnostic procedures.
Because of the significant variations in tumor locations and clinical presentation, a neurosurgeon will rely on Magnetic Resonance Imaging (MRI) to help to identify the type and exact location of a nerve sheath tumor. Other alternatives or complementary diagnostic procedures may include Computed Tomography (CT) and Positron Emission Tomography (PET) scans. All these modalities enable a neurosurgeon to make a decision regarding appropriate treatment approach for each particular case.
Sometimes the imaging results may not offer enough data to be certain about the type of tumor, to conclude whether or not the tumor is malignant. In that case, the physician will perform a biopsy. It is when a sample of the tumor cells is obtained from the body using a needle. The extracted sample then goes to a pathology lab, which will investigate the cells under a microscope and perform several tests to determine the type of tumor.
Treatment of Nerve Sheath Tumor
The treatment options for nerve sheath tumors depend on the stage of the tumor, location, and involvement of surrounding structures, such as peripheral nerves. Fortunately, benign tumors grow at a significantly slower rate, enabling doctors to administer non-invasive treatment methods. Otherwise, they might recommend surgery.
Doctors initially consider non-invasive treatment approaches for treating tumors, when indicated. The majority of benign nerve sheath tumors, that are smaller in size and do not interfere with the functioning of the vital structures, would be treated with observation, that includes repeat physical examinations and serial imaging.
As nerve sheath tumor growth progresses, it can enlarge to a degree when it starts to compress the nerve. As a result, a patient may feel pain, numbness, itching, burning or tingling. In that case, the doctor will consider surgery to remove the tumor cells and any other affected soft tissue. Ideally, a neurosurgeon will remove the tumor without interfering with the nerve. If the circumstances make it impossible to preserve the nerve, the doctor will attempt to repair it during the surgery.
Usually, surgeries involving schwannoma tumors make it easy for the surgeon to leave the nerve intact. Neurofibroma surgeries are more challenging because the growth takes place within the nerve cell’s center. That means a neurosurgeon will have first to open the nerve and remove the tumor from within. The incision damages the nerve, but the nerve has the ability to repair itself to restore the function.
The type of tumor and its location in the body, and the extent of the surgery all affect the recovery time after the procedure. The neurosurgeon will discuss the surgical procedure and recovery process before the operation in great detail. If the tumor is determined to be MPNST, the surgeon will coordinate with other physicians as needed to provide a comprehensive treatment plan.
When neurosurgeons cannot remove the tumor surgically, chemotherapy is another treatment option. Chemotherapy is used to shrink the growth, making its removal relatively more straightforward or even unnecessary. Based on the nature of the tumor, chemotherapy can be combined with radiation for effective treatment. Chemotherapy helps particularly when treating MPNST that has spread to other body parts.
Make an Appointment with CNSO
Although nerve sheath tumor is a slow-growing benign tumor in most of the cases, it’s critical to seek proper treatment as soon as possible to prevent the significant compression of neural structures or, in some instances, development of MPNST. The dedicated team Centers for Neurosurgery, Spine & Orthopedics will create comprehensive treatment plans for Northern NJ patients who have a nerve sheath tumor. Request an appointment today.