Nerve cancer involves abnormal growths in the cells that form nerves outside the brain and spinal cord, known as the peripheral nervous system. These tumors can affect any part of the body where peripheral nerves are present, including the arms, legs, head, neck, and torso. While some nerve tumors are non-cancerous, others are malignant and can spread. These cancers are relatively uncommon.
Types of Nerve Tumors
Nerve tumors are classified as benign (non-cancerous) or malignant (cancerous). Benign tumors grow slowly and do not spread, though they can still cause issues by pressing on surrounding nerves or tissues. Malignant tumors are aggressive, grow quickly, and can invade nearby structures or metastasize to distant sites.
Malignant Peripheral Nerve Sheath Tumors (MPNSTs) are the most common type of malignant nerve tumor in adults. They originate from cells forming the protective sheath around peripheral nerves. These aggressive soft tissue sarcomas can occur anywhere, often found in the deep tissues of the arms, legs, or trunk. Historically, MPNSTs were known by names like neurofibrosarcoma or malignant schwannoma.
Schwannomas and neurofibromas are benign peripheral nerve sheath tumors. Schwannomas arise from Schwann cells and often displace the nerve rather than encasing it. Neurofibromas originate from multiple cell types within nerve tissue and tend to encase nerve fibers. While most remain non-cancerous, a small percentage, particularly neurofibromas, can transform into MPNSTs, especially in individuals with certain genetic conditions.
Neuroblastoma is a distinct nerve cancer primarily affecting infants and young children. This cancer develops from immature nerve cells called neuroblasts, which are part of the sympathetic nervous system. Neuroblastomas commonly originate in the adrenal glands or along the sympathetic nerve chain in the abdomen, chest, neck, or pelvis.
Associated Symptoms and Risk Factors
Symptoms of nerve tumors often depend on the tumor’s location, size, and growth rate. A noticeable lump or swelling under the skin is common and may or may not be painful. As the tumor expands, it can press on nerves or surrounding tissues, leading to various neurological symptoms.
Pain, a burning sensation, numbness, or tingling in the affected limb or area are common symptoms. Weakness or loss of function in the body part supplied by the affected nerve can also occur. Dizziness or loss of balance may develop in some cases. These symptoms might worsen rapidly if the tumor is malignant and growing aggressively.
A primary risk factor for malignant nerve tumors is the genetic disorder Neurofibromatosis type 1 (NF1). This inherited condition, caused by a mutation in the NF1 gene, leads to multiple benign neurofibromas and café-au-lait spots on the skin. Approximately 8% to 13% of individuals with NF1 may develop an MPNST during their lifetime, accounting for up to 50% of all MPNST cases.
Previous exposure to radiation therapy is another risk factor for nerve cancers. MPNSTs can develop in areas previously treated with radiation, sometimes many years later. This risk is higher in individuals with NF1, suggesting increased sensitivity to radiation side effects.
The Diagnostic Process
Diagnosing nerve cancer begins with a physical examination and a review of the patient’s medical history. The healthcare provider assesses symptoms, checks for lumps or swelling, and performs a neurological exam to evaluate nerve function. These initial steps guide further investigations to pinpoint the cause of symptoms.
Imaging tests are important for visualizing the tumor and assessing its characteristics. Magnetic Resonance Imaging (MRI) is a preferred method, using strong magnets and radio waves to create detailed 3D images of nerves and surrounding tissues. Computed Tomography (CT) scans also provide detailed cross-sectional images, helping determine the tumor’s size and its relationship to nearby structures. Positron Emission Tomography (PET) scans may identify areas of increased metabolic activity, which can indicate cancerous tissue or detect spread.
A biopsy is the definitive method for confirming a nerve cancer diagnosis and identifying the tumor’s specific type and grade. During a biopsy, a small tissue sample is removed from the suspected tumor. A pathologist then examines this sample under a microscope to determine if cancer cells are present and classify the tumor. Depending on the tumor’s location and size, the biopsy may be performed with local or general anesthesia.
Common Treatment Approaches
Treatment for nerve cancer is complex and tailored to the tumor’s specific type, size, and location, as well as the patient’s overall health. The primary goal is to eliminate the cancer while preserving as much nerve function as possible. A multidisciplinary team of specialists collaborates on the treatment plan.
Surgery is the main treatment for malignant peripheral nerve sheath tumors, aiming for complete removal of the tumor along with a margin of healthy surrounding tissue. The surgeon works to achieve clear margins to reduce recurrence likelihood, while minimizing damage to nearby nerves and preserving function. Extensive surgery might be necessary depending on the tumor’s invasion into adjacent tissues.
Radiation therapy complements surgical treatment. This therapy uses high-energy X-rays or other radiation types to destroy cancer cells or inhibit their growth. Radiation may be administered before surgery to shrink a large tumor, making it easier to remove (neoadjuvant therapy). Alternatively, it can be used after surgery to target any remaining cancer cells (adjuvant therapy) to reduce recurrence risk.
Chemotherapy and targeted therapy are additional options, particularly for cancers that have spread or cannot be entirely removed surgically. Chemotherapy involves drugs that kill rapidly dividing cells, including cancer cells, and can be given orally or intravenously. Malignant peripheral nerve sheath tumors may not respond well to traditional chemotherapy, but it can slow tumor growth or manage metastatic disease. Targeted therapy drugs specifically attack vulnerabilities in cancer cells, often by interfering with molecules involved in tumor growth and survival, causing less harm to healthy cells.
Understanding Prognosis and Recovery
The prognosis for individuals with nerve cancer, particularly malignant peripheral nerve sheath tumors, varies based on several factors. These include the tumor’s specific type and grade, its size and location, and whether it has spread at diagnosis. The completeness of surgical removal, indicated by clear surgical margins, also influences the long-term outcome.
Recovery from nerve cancer treatment can be a prolonged process, especially after extensive surgery or other aggressive therapies. Patients may experience pain, weakness, numbness, or limited range of motion in the affected area. Rehabilitation services, such as physical and occupational therapy, help patients regain function, manage pain, and improve quality of life. These therapies assist in strengthening muscles, improving balance, and adapting to any lingering physical limitations.