Spinal neurofibromas are benign growths that develop on nerves, most frequently in the spine. These tumors can lead to various issues by pressing on surrounding nerves or the spinal cord. Their presence can cause a range of symptoms, impacting sensation and movement.
What Spinal Neurofibromas Are
Spinal neurofibromas are benign tumors originating from Schwann cells, which form the protective sheath around nerve fibers. These tumors are commonly found along nerve roots extending from the spinal cord, often appearing in a “dumbbell” shape with parts inside and outside the spinal canal. Most are non-cancerous.
A strong association exists between spinal neurofibromas and Neurofibromatosis Type 1 (NF1), a genetic disorder. NF1 arises from a mutation in the NF1 gene, which produces neurofibromin, a protein regulating cell growth. When this gene is altered, cells can proliferate, leading to tumor formation. While most neurofibromas remain benign, a small percentage in NF1 patients can undergo malignant transformation into malignant peripheral nerve sheath tumors (MPNSTs).
Recognizing Symptoms
Symptoms of spinal neurofibromas arise when the growing tumor presses on or irritates spinal nerves or the spinal cord. These include localized pain in the back or neck, numbness, or tingling sensations in areas supplied by the affected nerves. Muscle weakness can also occur in corresponding body regions.
The tumor’s size and exact location within the spine determine specific symptoms. For instance, a tumor in the cervical (neck) region might lead to symptoms in the arms, while one in the lumbar (lower back) area could affect the legs. In rarer cases, significant compression of the lower spinal cord can result in a loss of bladder or bowel control.
How Spinal Neurofibromas Are Diagnosed
Diagnosing spinal neurofibromas typically begins with a medical history and a physical examination, including a neurological assessment. During the physical exam, applying light pressure to the tumor might elicit an electric shock-like sensation if it is near the surface.
Imaging tests are primary tools for visualizing these tumors. Magnetic Resonance Imaging (MRI) is often preferred, providing detailed images of the spinal cord and nerves. Computed Tomography (CT) scans and X-rays can also be used, revealing well-defined masses and sometimes showing widening of the neural foramen where the nerve exits the spine. While imaging provides strong indications, a biopsy may be performed to confirm the diagnosis and rule out other conditions or malignancy.
Managing Spinal Neurofibromas
Management of spinal neurofibromas is individualized, considering tumor size, location, symptoms, and overall patient health. For small, asymptomatic tumors, a “watchful waiting” approach is often recommended. This involves regular monitoring with physical exams and imaging, typically yearly MRI scans, to observe any changes.
Surgical intervention, such as a laminectomy, is a common treatment for symptomatic or growing tumors. This procedure involves removing a portion of the vertebral bone (lamina) to access and excise the tumor, thereby relieving pressure on the spinal cord or nerves.
Radiation therapy, particularly stereotactic radiosurgery (SRS), may be considered when surgery is not feasible or for tumors difficult to access. SRS delivers highly concentrated radiation doses with pinpoint accuracy to shrink the tumor while minimizing damage to surrounding healthy tissue. Medication can also be used to manage symptoms like neuropathic pain, which is nerve-related and often described as a burning sensation.