Schwannoma
What is it?
A schwannoma, also known as neurilemmoma, is a benign, encapsulated neoplasm derived from Schwann cells (glial cells that form the myelin sheath on axons outside the brain). Along with neurofibroma, schwannoma constitutes one of the two most common benign peripheral nerve sheath tumors. The peripheral nervous system can be defined as nervous tissue outside the brain and spinal cord. Spinal schwannomas typically arise from spinal nerve roots, and it is the most common nerve sheath tumor of spine. They have a peak incidence in the fifth through seventh decades. There is no significant sex predilection.
Symptoms
As spinal schwannomas usually arise from the dorsal sensory roots, patients commonly present with pain. Radicular sensory changes also occur. Weakness is less common. Myelopathy may occur if the lesion is large.
Diagnosis
To determine if a patient has a schwannoma, a doctor will test reflexes, muscle strength and ability to feel sensations on the skin, in addition to the X-ray, CT or MRI scans. Biopsy to determine whether the tumor is cancerous may be necessary.
Treatment
Schwannomas are slow growing lesions but can nevertheless be debilitating. They almost never undergo malignant change. Surgery is the treatment of choice. Gross total resection is usually the best curative option.