Receiving a diagnosis of acoustic neuroma often raises many questions: Is it cancer? Does it always affect hearing? How does it progress? What treatment options are available today?
The first thing to do is to put it into context. Acoustic neuroma is a benign tumor and is usually slow-growing, but it can significantly affect quality of life if it is not detected and monitored in time. In terms of frequency, it is considered rare, with an estimated annual incidence of around 7.8–12.4 cases per million inhabitants.
Next, we will look at what exactly it is, what the most common symptoms are, how it is diagnosed, and what the treatment options are.
What is acoustic neuroma?
Acoustic neuroma is a non-cancerous (benign) tumor that develops in the nerve that connects the ear to the brain and is involved in hearing and balance. It usually grows slowly and, as it increases in size, it can press on the auditory and balance nerves, causing symptoms that may be mild or go unnoticed at first.
This is why it is sometimes described as an “ear tumor,” although it actually originates in the nerve (not in the ear structure itself) and is located very close to the inner ear. Strictly speaking, we are talking about a tumor of the nerve that transmits auditory and balance information from the ear to the brain.
An important point: because it is benign, it does not spread to other organs as malignant tumors do. However, “benign” does not mean “irrelevant”: if the tumor grows and is not treated when appropriate, it can damage nearby structures, causing sequelae and complications (e.g., worsening hearing or impaired balance), hence the importance of monitoring and treatment when indicated.
Is acoustic neuroma the same as vestibular schwannoma?
Yes. Acoustic neuroma and vestibular schwannoma are used in practice to refer to the same tumor.
- “Schwannoma” refers to the origin of the tumor: it grows from Schwann cells, which cover and protect the nerves.
- “Vestibular” refers to the portion of the nerve related to balance, which is usually the most affected.
- “Acoustic” is the historical term linked to hearing.
Therefore, it is very common for patients to find both terms in medical reports, articles, or online searches: acoustic neuroma = vestibular schwannoma.
Most common symptoms of acoustic neuroma
The symptoms of acoustic neuroma can be subtle at first and appear gradually, which sometimes delays suspicion. In addition, many symptoms can be confused with common middle ear or inner ear problems. Even so, there are typical signs:
- Hearing loss in one ear (usually progressive).
- Ringing in the ear (tinnitus), usually on the affected side.
- Dizziness, vertigo, or balance problems (feeling of instability, feeling of leaning to one side).
Depending on the size, location, and progression, other less common or later symptoms may appear, such as:
- Feeling of “clogged ears.”
- Difficulty understanding conversations (especially with background noise).
- Unsteadiness when walking.
- In larger tumors, nearby nerves may be affected, with possible changes in facial sensitivity or facial weakness (not common at first, but may occur if there is compression).
Acoustic neuroma: possible sequelae
When discussing the sequelae of acoustic neuroma, it is important to distinguish between two scenarios:
- Sequelae due to the evolution of the tumor itself (if it progresses): worsening of hearing, persistent tinnitus, imbalance.
- Sequelae related to treatment, which depend on the option chosen (observation, surgery, or radiation therapy/radiosurgery), the size of the tumor, and individual factors. At this point, a personalized plan and an experienced team are key.
If you have compatible symptoms or doubts, it is advisable to see specialists in acoustic neuroma (otorhinolaryngology and neurosurgery) to assess the situation with specific tests.
How is acoustic neuroma diagnosed?
The diagnosis of acoustic neuroma usually combines clinical findings (symptoms) with tests that evaluate hearing and, above all, imaging.
In general, the process includes:
- Clinical evaluation and examination: symptoms such as unilateral hearing loss, tinnitus, vertigo, or instability are reviewed, and their progression is assessed.
- Hearing tests (audiometry): these help to evaluate hearing loss, its pattern, and its functional impact. They are important for both diagnosis and follow-up.
- Contrast-enhanced magnetic resonance imaging (MRI): this is the gold standard test for confirming the presence of the tumor, allowing it to be visualized accurately and follow-up or treatment to be planned.
In many cases, once the diagnosis has been confirmed, a follow-up plan with serial MRIs is established if observation is chosen (especially when the tumor is small and the symptoms are mild). In addition, depending on the patient and the physician’s criteria, the study may be supplemented with other tests, although MRI and audiological evaluation are usually the cornerstones of the approach.
Treatment of acoustic neuroma
There is no single treatment that is valid for everyone. The choice depends on variables such as:
- Tumor size and location.
- Growth rate.
- Symptoms (hearing, balance, impact on daily life).
- Age and general health.
- Patient preferences after learning about the risks and benefits.
In general, three strategies are considered:
- Observation and monitoring: when the tumor is small, not growing, or symptoms are mild, surveillance with periodic checkups and MRIs may be recommended. This option is used precisely because the tumor is usually benign and slow-growing.
- Surgery: this aims to remove the tumor (either completely or partially, depending on the case). It is a well-established option, but requires a highly individualized assessment due to the potential risks, especially in larger tumors or those close to nerves (hearing, balance, facial nerve).
- Stereotactic radiotherapy/radiosurgery: this is where technology has made a significant leap forward. These techniques allow the tumor to be treated with precision in order to control its growth, minimizing the impact on healthy tissue. The MSD Manual considers stereotactic radiotherapy as an alternative for small tumors or to treat remnants after surgery, with the aim of stopping growth.
In addition to these alternatives, there are now advanced radiosurgery technologies focused on high precision. IRCA has ZAP-X, a high-precision, non-invasive stereotactic radiosurgery system for the brain, with the ability to control the dynamics of irradiation to help protect surrounding healthy structures. In this approach, the goal is to treat with precision and with an approach that prioritizes quality of life, always after a complete and individualized medical evaluation.
In clinical practice, benign brain tumors with defined boundaries (such as acoustic neuromas) may be considered suitable for treatment with radiosurgery in selected cases.
We should also clarify that according to EANO guidelines, surgery is the recommended option for large Koos III-IV tumors, and for small Koos I-II tumors, the recommendation is treatment with radiosurgery. This is due to the proven advantages of radiosurgery over surgery, such as reduced risk of facial paralysis and hearing loss, along with 95% effectiveness in slowing tumor growth.
For more information on this approach, please refer to the related resource: Benign Tumors.
SOURCES:
SciELO (Journal of Otorhinolaryngology and Head and Neck Surgery). Acoustic neuroma (vestibular schwannoma). https://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-48162008000400012
MedlinePlus in Spanish. Acoustic neuroma. https://medlineplus.gov/spanish/acousticneuroma.html
MedlinePlus (Medical Encyclopedia, Spanish). Acoustic neuroma. https://medlineplus.gov/spanish/ency/article/000778.htm
MSD Manual (general public, Spanish). Vestibular schwannoma (acoustic neuroma). https://www.msdmanuals.com/es/hogar/trastornos-otorrinolaringol%C3%B3gicos/trastornos-del-o%C3%ADdo-interno/schwannoma-vestibular
MSD Manual (professional, Spanish). Vestibular schwannoma. https://www.msdmanuals.com/es/professional/trastornos-otorrinolaringol%C3%B3gicos/trastornos-del-o%C3%ADdo-interno/schwannoma-vestibular
Learn Skull Base: Vestibular Schwannoma https://aprenderbasedecraneo.com/enfermedades/schwannoma-vestibular/
Ciencia Latina – Multidisciplinary Journal: “Novel fundamentals of diagnosis and treatment of acoustic neuroma” https://ciencialatina.org/index.php/cienciala/article/view/5490/8304