If you’ve been diagnosed with a benign nerve sheath tumor, you probably have questions about the condition and how best to approach it. The nervous system is complex, but by doing some research and talking with your doctor, you can better understand benign nerve sheath tumors and feel more confident about your health.
What follows is an overview of benign nerve sheath tumors, as well as a comparison of the two most common types: schwannomas and neurofibromas. You should use this guide to form questions for your doctor.
Overview of a Benign Nerve Sheath Tumor
Schwannomas and neurofibromas are two of the most common types of benign nerve sheath tumors. In order to understand these kinds of tumors, it is helpful to first understand the basic anatomy of the nervous system.
The nervous system consists of two parts, the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS contains the brain and the spinal cord, while the PNS contains nerves all over the body that send signals to the CNS. These signals are sent with the help of nerve fibers that are covered in myelin, a substance also known as the “nerve sheath.” Myelin protects nerve fibers and helps them send fast and efficient signals, but sometimes the cells that create myelin can malfunction and grow uncontrollably, thus forming a nerve sheath tumor.
While some nerve sheath tumors are aggressive, most are benign, meaning they grow very slowly and aren’t an immediate health risk. Schwannomas and neurofibromas are two examples of benign nerve sheath tumors.
What Is a Schwannoma?
Schwannomas and neurofibromas are two very similar conditions, but there are slight differences in their symptoms, diagnosis and treatment. Most of these tumors are solitary and occur in isolation of a systemic genetic problem. Such tumors are termed “sporadic.” Neurofibromas and schwannomas can be associated with a genetic condition called neurofibromatosis (NF), but each is seen in a different subtype.
Schwannomas, are benign tumors that grow slowly – and only very rarely become malignant. In addition, their position relative to the affected nerve fiber is different from neurofibromas; they typically displace the nerve root, but do not envelope it. They are associated with Neurofibromatosis Type II, in which patients can have multiple schwannomas throughout their bodies and are predisposed to some other kinds of brain tumors.
What Is a Neurofibroma?
Neurofibromas, on the other hand, are associated with NF Type I. This subtype of benign nerve sheath tumor is also at very low risk of becoming malignant. Neurofibromas do not simply displace the nerve root, but rather encase it. Patients with NF1 have multiple neurofibromas and often have characteristic birthmarks called “cafe au lait” spots.
How They Compare
Although there are some anatomic considerations that may affect surgical technique, treatment of neurofibromas and schwannomas is essentially the same.
Schwannomas and neurofibromas have a common diagnostic process. If you present your doctor with some combination of the known symptoms, he or she will likely perform a physical examination and an MRI to visualize the affected area. If you have multiple tumors or other findings that indicate a genetic syndrome, genetic testing may be advised.
Treatment options are the same for both schwannomas and neurofibromas. The first consideration in treating a benign nerve sheath tumor is whether it is symptomatic or growing. If the tumor doesn’t bother you and it poses no threat, the best thing to do may simply be to leave it alone while monitoring it with periodic MRIs.
If you and your doctor decide to actively treat the benign nerve sheath tumor, then surgical removal is usually the best choice. If, for whatever reason, you and your doctor decide you cannot tolerate surgery because of a medical condition, radiosurgery is an option. Talk with your doctor to better understand your benign nerve sheath tumor and the options available to you.
Schwannomas and neurofibromas are benign nerve sheath tumors that, due to their similarity, sometimes cause confusion. From the patient’s perspective, when considering surgery, the reasons that your doctor might advise you to surgically remove these tumors are the same.