Acoustic Neuromas

An acoustic neuroma is benign growth that arises from the vestibulo-cochlear nerve. Not every patient needs to be treated right away. Small tumors detected incidentally or associated with very minor symptoms can be observed with interval MRI scans and follow-up audiograms. However, growing tumors that are observed but not treated may cause significant problems and may be harder to treat as symptoms progress. Early detection and treatment of growing tumors offers the best chance of long-term cure and functional recovery.



Small incidental tumors or ones associated with very minor symptoms may be observed with serial MRI scans and follow-up audiograms to follow the tumor. At UCSF, the Skull Base Surgery Team will make recommendations based on an individual patient’s findings, presentation, and health status, and personal preferences


The goal of microsurgery is to resect as much tumor as possible without injuring the brain and nerves that control facial function, hearing, and balance. There are many different surgical approaches to the tumor, including:

  • The Retrosigmoid Approach: This approach is used when the tumor is located mostly outside the internal auditory canal and adjacent to the brain stem. It can be effective for hearing preservation and decompressing the brain when a large tumor has grown.
  • The Translabyrinthine Approach: This is an approach through the mastoid and semicircular canals to the internal auditory canal, where the tumor is found. The translabyrinthine approach provides direct exposure of the tumor without the need to retract normal brain. It is only indicated for patients who have profound hearing loss or very large tumors with a significant intracanalicular component.
  • The Middle Fossa Approach: This approach has the best record for preserving hearing when resecting tumors less than 2 cm in diameter. This approach is limited to relatively small acoustic neuromas that are mostly in the inner auditory canal and involves the retraction of the temporal lobe to access the tumor from above.


The goal of radiation treatment is to stop tumor growth without injuring the important structures surrounding the tumor. Radiation will not remove a tumor, but may shrink it after time. In general, there is no clear advantage of one modality over the other, but tumors with a specific size and shape may be more effectively treated with one type of radiosurgery or radiotherapy. Accordingly, centers such as UCSF, which have all modalities of radiation treatment available (including Gamma Knife Radiosurgery, Fractionated Stereotactic Radiotherapy, and LINAC Radiosurgery), offer the most comprehensive approach.


Understanding the molecular features that predict growth of sporadic vestibular schwannoma is an important goal at UCSF. Recently, our scientific team has established a novel method to study the genetics of each patient’s tumor in order to evaluate the tumor’s sensitivity to various drugs. In addition to offering treatment and management options for our patients, our division works closely with scientists to understand the molecular features that predict growth of sporadic vestibular schwannomas and develop methods to study the genetics of each patient’s tumor to determine the most effective drug to use against the acoustic neuroma.