Schwannoma

Overview

Schwannoma is sometimes known as neurilemmomas or neuromas, is a tumor that arises from Schwann cells in the peripheral nervous system or nerve roots. Schwannomas are most found in the nerve that connects the brain to the inner ear, also known as vestibular schwannoma. Schwannomas are often slow growing. 

Schwann cells aid in the transmission of nerve impulses. They protect and maintain peripheral nerves by wrapping around them. A schwannoma is a tumor that develops from a single bundle or fascicle within the main nerve and displaces the remainder of the nerve. When a schwannoma grows, it affects more fascicles, making eradication more difficult. 

Schwannomas can arise at any age and in any part of the body. Although they are rarely malignant, they can cause nerve damage and muscular weakness. Cancerous schwannomas most commonly damage the sciatic nerve in the leg, the brachial plexus nerves in the arm, and the sacral plexus nerve group in the lower part of the back. If one happens to notice any strange lumps or numbness, consult a medical professional.

Symptoms

The signs and symptoms of schwannomas can go undetected for years. The severity and frequency of symptoms may vary among individuals. The manifestation of symptoms changes significantly as these tumors have slow growth and can develop in various parts of the body. For instance:

• Sciatic nerve schwannomas can cause low back pain that radiates down the leg.
• Tumors of the facial nerve can interfere with eating, eye movement, and taste sensations, as well as induce facial paralysis.
• Vestibular schwannomas can cause hearing and balance problems, as well as ringing sensations or tinnitus.

Generally, common signs and symptoms of a schwannoma include:

• Paresthesia, characterized by a pins–and–needles sensation.
• The presence of a visible lump that may be tender when pressure is applied.
• Numbness.
• Muscles weakness.
• Aching, burning, or stabbing pain.

If any of the signs and symptoms persist, consult a healthcare provider for proper diagnosis and treatment. In cases where the doctor recommends monitoring the tumor instead of pursuing treatment, it is necessary to schedule regular visits, at least once a year. Imaging tests will be required to monitor the growth and status of the tumor. 

Those who have schwannoma and experience new or worse symptoms, it is important to consult the healthcare provider for guidance on how to handle the changes in the condition.

Causes

Studies on genetics have revealed that the NF2 gene located on chromosome 22 plays a crucial role in the formation of schwannomas. Certain genetic disorders such as Carney complex, neurofibromatosis 2 (NF2), and schwannomatosis have been linked to the development of schwannomas. However, about 90% of occurrences are considered sporadic, meaning they arise randomly without a known cause. The exact cause of this condition is still unknown.