Acoustic neuroma: The most common inner ear tumor

Brent Wilkerson, MD

Neurotology, Otolaryngology

Tumors, whether benign or malignant, can form essentially anywhere within the body. A tumor is simply a mass that is created when cells don’t die when they normally would, but instead continue to grow and divide. There are even kinds of tumors that grow within the ear, including one kind called an acoustic neuroma, or vestibular schwannoma.

What is an acoustic neuroma? How are they diagnosed and treated? Brent Wilkerson, MD, answered common questions about acoustic neuromas, including signs, symptoms and more.

What is an acoustic neuroma?

“Acoustic neuromas, also known as vestibular schwannomas, are the most common inner ear tumor,” said Dr. Wilkerson. “They originate on the nerves that control balance within the inner ear and internal auditory canal, but they can eventually grow inward toward the brain.”

Acoustic neuromas are technically benign, meaning noncancerous, but they can still cause significant problems due to their size and growth rate, as the inner ear simply has no space for it.

What are the symptoms of inner ear tumors?

“The first signs of tumor growth within the inner ear are going to be hearing loss, ringing in the ear (also called tinnitus) and dizziness,” said Dr. Wilkerson. “If the tumor grows inward and puts pressure toward the brain, you might also experience headaches, facial paralysis, facial numbness, unsteadiness or even a loss of vision.”

How is an acoustic neuroma diagnosed?

Since hearing loss as a symptom of an acoustic neuroma will be focused only on the ear where the tumor is growing, a hearing test that shows hearing loss far more significant in one ear and not the other will be a sign for more detailed testing to find out the reason.

An acoustic neuroma is usually diagnosed after an MRI.  If an acoustic neuroma is found on an MRI, a battery of balance testing may also be ordered by your treating physician. 

How is an acoustic neuroma treated?

“First, it’s important to remember that acoustic neuromas are benign tumors,” said Dr. Wilkerson. “They don’t spread to other parts of the body. They still need to be treated immediately, however, as the pressure the growing tumor can place on balance and hearing nerves and the brain can cause serious discomfort, pain and even lasting damage.”

Treatment of an acoustic neuroma focuses on two things: The preservation of life and preserving the essential structures within the inner ear. Acoustic neuroma patients are treated using a team approach, where a specialist in neuromonitoring, an anesthesiologist, a specially trained surgical nurse, a neurosurgeon and a neurotologist (or ear specialist) work together to safely remove the tumor and hopefully help the patient recover lost hearing and return to normal life.

There are three treatment options for acoustic neuromas:

• Observation: In very specific situations, your doctor may want to monitor the existing tumor for growth over a certain period of time. Some acoustic neuromas do stop growing (temporarily or permanently), and for those who are elderly or have other medical conditions, observation may be recommended.
• Stereotactic radiosurgery: In this form of treatment, the delivery of a single dose of focused radiation is used to hopefully stop growth of small or medium tumors. This treatment takes several hours and is generally outpatient.
• Microsurgery: This is generally the recommended treatment for many cases of acoustic neuroma and involves removing the entire tumor from within the ear. Generally, the surgery takes many hours, involves overnight observation in a specialized neurological ICU afterward and may include hospitalization for up to a week post-surgery to watch for potential complications.

Each of these treatment options has its own risks. Stereotactic radiosurgery and microsurgery are fairly serious procedures and hold the possibility of serious complications. Before treatment begins, a person diagnosed with acoustic neuroma will meet with a neurotologist and a neurosurgeon to dig into the specific risks, discuss the reasons this treatment has been recommended and what complications are possible.

“Great advances have been made in our ability to safely remove even larger acoustic neuromas,” said Dr. Wilkerson. “Technologies like microsurgery, stereotactic radiosurgery, lasers and nerve monitors really give us more confidence than ever in successfully treating acoustic neuromas and offering our patients a return to a normal life.”