Schwannomas are typically benign nerve sheath tumors that develop from Schwann cells—the cells responsible for producing the protective myelin sheath that surrounds nerves after they exit the b rain. Usually noncancerous, schwannomas can grow slowly over time and press on adjacent nerves or tissues, leading to pain, numbness, or functional impairment.
Most schwannomas are isolated tumors, but in some cases, they are associated with genetic conditions such as neurofibromatosis type 2 (NF2) or schwannomatosis. With early diagnosis and appropriate treatment, schwannomas are highly manageable and often curable.
What Are Schwannomas?
A schwannoma—also called a neurilemmoma—is a tumor that grows on a nerve. These tumors are usually encapsulated and arise from a single bundle of nerve fibers. Schwannomas can occur on cranial nerves, spinal nerves, or peripheral nerves throughout the body.
One of the most well-known types is the vestibular schwannoma ( also called acoustic neuroma), which affects the eighth cranial nerve responsible for hearing and balance.
Other schwannomas may appear in the arms, legs, spine, or along any nerve pathways.
Schwannomas are usually:
- Slow-growing
- Non-invasive
- Benign (noncancerous)
Who Gets Schwannomas and When?
Schwannomas can affect people of any age, but they are most commonly diagnosed in adults between 30 and 60 years old. They occur equally in men and women and are typically sporadic, meaning they occur without an identifiable cause.
However, in some cases, schwannomas may be part of a genetic syndrome, particularly in younger individuals with multiple or bilateral tumors. These include:
- Neurofibromatosis type 2 (NF2)
- Schwannomatosis
Most schwannomas are diagnosed after symptoms develop due to compression of surrounding nerves or tissues.
