On this page
What Is a Schwannoma Tumor?
A schwannoma tumor is a rare, slow-growing tumor that originates in Schwann cells, which form the protective myelin sheath around your nerves.
This sheath insulates nerves and enables the transmission of nerve signals throughout your body.
Most schwannomas are benign, with only about 2.5 percent becoming malignant. However, as they grow, they may compress nerves and cause various symptoms.
Schwannomas can develop anywhere in the body, but are most commonly found in areas including:
- Adrenal glands.
- Behind the knee.
- Bone.
- Chest.
- Gastrointestinal (GI) tract.
- Head.
- Inner ear (schwannomas make up about 60 percent of cases).
- Liver.
- Lymph nodes.
- Pancreas.
- Spine.
- Torso.
- Thyroid.
What causes schwannoma tumors?
Most schwannomas occur sporadically, without a known cause. However, about 10 percent of cases are linked to genetic conditions including:
- Carney complex.
- Neurofibromatosis type 2 (NF2).
- Schwannomatosis.
Schwannoma tumor risk factors and complications
Schwannoma tumor risk factors
People with NF2 or schwannomatosis are more likely to develop multiple schwannomas. Schwannoma tumors are more likely to occur in people due to:
- Age — Schwannomas are more common in adults who are in their 50s and 60s.
- Genetic conditions — NF2, schwannomatosis, and Carney complex increase your risk.
Complications of schwannoma tumors
The severity of complications from a schwannoma tumor depend on the tumor's size and location. Some complications may improve after the tumor has been removed, while others may require further medical intervention.
Potential complications include:
- Asymptomatic mass.
- Balance difficulties.
- Difficulty swallowing.
- Distal muscle weakness in your hands, arms, feet, and legs.
- Facial numbness, pain, or paralysis.
- Hearing loss or tinnitus (ringing in the ears).
- Lower back pain that radiates down your legs, mimicking symptoms of a herniated disc.
- Neurological deficits.
- Numbness, tingling, or burning sensations.
- Tarsal or carpal tunnel syndrome (from schwannomas in your wrist or ankle).
- Thoracic outlet syndrome, which is caused by compression of arteries, veins, and nerves in your upper chest.
Back to top
What Are the Signs and Symptoms of a Schwannoma Tumor?
Symptoms of a schwannoma tumor depend on its location and size. Some benign schwannomas may not cause any symptoms.
Common schwannoma symptoms include:
- A lump, bump, or mass that may be tender to the touch or painless.
- Back pain that worsens when lying down.
- Difficulty moving your eye(s) or swallowing.
- Dizziness and balance issues.
- Facial paralysis.
- Hearing loss or ringing in your ears (vestibular schwannoma).
- Numbness.
- Pain that radiates down your legs.
- Tingling or burning sensations.
- Weakness in the affected area.
Back to top
How Do You Diagnose a Schwannoma Tumor?
Because schwannoma tumors grow slowly, they may remain undiagnosed for years. On average, a diagnosis is made about five years after symptoms appear.
What to expect during your visit
If your doctor suspects a schwannoma tumor, they will conduct a thorough physical examination, testing your reflexes, muscle strength, and skin sensations.
Your doctor may also order tests, including:
- Biopsy — A small sample of tumor tissue is analyzed under a microscope.
- Imaging scans — CT scans, x-rays, and MRIs help determine the tumor's size, location, and whether it has spread.
Back to top
How Do You Treat a Schwannoma Tumor?
Treatment for a schwannoma tumor depends on the size, location, and whether it is causing symptoms.
Watchful waiting for schwannoma tumors
If your tumor is benign, slow-growing, and is not causing symptoms, your doctor may recommend regular monitoring without immediate treatment.
Surgery for schwannoma tumors
Most schwannomas can be removed through minimally invasive microsurgery, which uses a high-powered microscope. Your surgeon may also use ultrasound to help detect schwannomas under your skin before surgery. Larger tumors may require more extensive surgery.
Stereotactic radiosurgery (SRS) for schwannoma tumors
Stereotactic radiosurgery (SRS) is an option for spinal schwannomas. This noninvasive technique uses precisely targeted radiation beams to shrink the tumor while sparing healthy tissue. Because SRS does not require incisions, it has no recovery time.
Radiation and chemotherapy for schwannoma tumors
If a schwannoma is malignant or in a location where complete surgical removal is difficult, radiation therapy and chemotherapy may be used to slow tumor growth and prevent recurrence.
How effective is schwannoma treatment?
After treatment, your doctor may recommend routine MRIs to check for any tumor regrowth.
Your prognosis depends on factors such as tumor location, malignancy, and the success of surgical removal. If a benign schwannoma is completely removed, most people recover fully and experience no recurrence.
However, some people may have long-term side effects, such as muscle weakness or permanent hearing loss, particularly if the tumor was in the inner ear.
Although surgery and radiation are effective at treating schwannomas, they do not prevent the development of future tumors, especially in individuals with genetic conditions.
Back to top
Why Choose UPMC for Schwannoma Care?
When you choose UPMC for schwannoma care, you have access to a team of specialists with advanced training and expertise in all types of tumor treatment. As a high-volume surgery center, we have the experience, technology, and facilities required to provide expert care for patients with any type of tumor — from common to complex.
Back to top