Schwannoma: Symptoms, Causes, Treatment

What are the symptoms of a schwannoma?

Schwannomas, also known as neurilemomas, are benign tumors that arise from Schwann cells, which produce the myelin sheath covering nerves. The symptoms of a schwannoma depend on the location of the tumor and the nerves affected. Common symptoms include:

• Hearing Loss: If the schwannoma affects the acoustic nerve (vestibulocochlear nerve), it can lead to hearing loss or tinnitus (ringing in the ears). This is often seen in vestibular schwannomas (also known as acoustic neuromas).
• Balance Issues: Tumors affecting the vestibular nerve may cause dizziness, balance problems, or unsteadiness.
• Numbness or Tingling: Schwannomas that compress peripheral nerves can cause numbness, tingling, or a “pins and needles” sensation in the area served by the affected nerve.
• Pain: The tumor may cause localized pain or discomfort if it presses on surrounding tissues or nerves.
• Weakness: Weakness in the muscles controlled by the affected nerve may occur if the schwannoma impinges on motor nerves.
• Visible Mass: In some cases, a schwannoma may present as a palpable mass under the skin, particularly if it is a cutaneous schwannoma.
• Localized Symptoms: Depending on the tumor’s location, schwannomas can lead to symptoms specific to the affected nerve, such as difficulty swallowing if it involves the glossopharyngeal nerve.

Symptoms often develop gradually and may become more noticeable over time as the tumor grows.

What are the causes of a schwannoma?

Schwannomas are typically caused by the abnormal growth of Schwann cells, which produce the myelin sheath around nerves. The precise cause of this abnormal growth is not always clear, but several factors may contribute:

• Genetic Mutations: Schwannomas often result from mutations in genes that regulate cell growth. For example, mutations in the NF2 gene (Neurofibromatosis Type 2) are associated with the development of multiple schwannomas, particularly vestibular schwannomas.
• Genetic Conditions: Neurofibromatosis Type 2 (NF2) is a genetic disorder that increases the risk of developing schwannomas, particularly vestibular schwannomas. NF2 is caused by mutations in the NF2 gene, which leads to the development of tumors in the nervous system.
• Radiation Exposure: Exposure to high levels of radiation, particularly to the head or neck, has been linked to an increased risk of developing schwannomas. This is believed to be due to the damage to Schwann cells from radiation therapy.
• Family History: A family history of schwannomas or related genetic disorders can increase the risk of developing these tumors. Inherited conditions like Neurofibromatosis Type 2 can predispose individuals to schwannomas.
• Spontaneous Genetic Changes: In some cases, schwannomas may develop due to spontaneous genetic mutations that occur without a known genetic predisposition or external factors.

While these factors can contribute to the development of schwannomas, the exact cause in many cases remains unknown.

What is the treatment for a schwannoma?

The treatment for a schwannoma depends on several factors, including the tumor’s size, location, symptoms, and whether it is causing functional impairments. Common treatment options include:

• Observation: For small, asymptomatic schwannomas, regular monitoring with imaging studies (like MRI) may be sufficient. This approach is often chosen when the tumor is not causing significant symptoms or complications.
• Surgery: If the schwannoma is causing symptoms or is large enough to warrant intervention, surgical removal is a common treatment. The goal of surgery is to remove the tumor while preserving as much function of the affected nerve as possible. The success of surgery can depend on the tumor’s location and its relationship with surrounding structures.
• Radiation Therapy: For tumors that cannot be surgically removed or in cases where surgery is not feasible, radiation therapy may be an option. This can help to shrink the tumor or slow its growth. Stereotactic radiosurgery, such as Gamma Knife or CyberKnife, is often used for tumors like vestibular schwannomas.
• Medications: Although there are no specific medications to treat schwannomas, pain relief or management of symptoms may be addressed with medications. If the tumor is associated with neurofibromatosis, treatment may also focus on managing related conditions.
• Rehabilitation: Post-treatment rehabilitation, including physical therapy or occupational therapy, may be necessary to help patients regain function or adapt to any changes resulting from the tumor or its treatment.

The choice of treatment is individualized based on the specific characteristics of the schwannoma and the overall health of the patient. Regular follow-up with healthcare providers is essential to monitor for any recurrence or complications.